Lout 3.17.

git-svn-id: http://svn.savannah.nongnu.org/svn/lout/trunk@2 9365b830-b601-4143-9ba8-b4a8e2c3339c

1 files changed, 3845 insertions, 0 deletions

diff --git a/include/diagf b/include/diagf
new file mode 100644
index 0000000..18b888a
--- /dev/null
+++ b/include/diagf
@@ -0,0 +1,3845 @@
+
+###############################################################################
+#                                                                             #
+#  Lout @Diag package for drawing diagrams                                    #
+#  Version 1.0 (July 1996)                                                    #
+#  Jeffrey H. Kingston                                                        #
+#                                                                             #
+#  Based on Version 2.0 of the @Fig package (Jeffrey H. Kingston, Dec 1992).  #
+#                                                                             #
+###############################################################################
+
+@SysPrependGraphic { diagf.lpg }
+@SysInclude { diagf.etc }
+
+export @Diag
+def @DiagSetup
+    named save		             	{ no	           	}
+    named maxlabels             	{ 200           	}
+
+    import @Geometry named outline
+	named margin {}
+	named shadow {}
+	named sides {}
+	named angle {}
+					{ box			}
+    named margin			{ 0.6f          	}
+    import @Geometry named shadow	{ 0.4f          	}
+    import @Geometry named sides	{ 3			}
+    import @Geometry named angle	{ "dup 180 exch div"	}
+    named translate			{			}
+    named outlinestyle
+	named solid   { "/ldiagsolid"   }
+	named dashed  { "/ldiagdashed"  }
+	named cdashed { "/ldiagcdashed" }
+	named dotted  { "/ldiagdotted"  }
+	named noline  { "/ldiagnoline"  }
+					{ solid         	}
+    import @Geometry named outlinedashlength	{ 0.2f		}
+    import @Geometry named outlinewidth
+	named thin   { 0.04 ft }
+	named medium { 0.08 ft }
+	named thick  { 0.12 ft }
+					{ thin	         	}
+    named paint                 	{ nopaint       	}
+    named font				{			}
+    named break				{			}
+    named format right @Body    	{ @Body         	}
+
+    named valign			{ ctr           	}
+    named vsize                 	{               	}
+    named vindent			{ ctr           	}
+    named vstrut
+	named no  { 0.0f }
+	named yes { 1.0f }
+					{ no            	}
+    named vmargin               	{               	}
+    named topmargin             	{               	}
+    named footmargin            	{               	}
+
+    named halign			{ ctr           	}
+    named hsize                 	{               	}
+    named hindent			{ ctr           	}
+    named hstrut
+	named no  { 0.0f }
+	named yes { 1.0f }
+					{ no            	}
+    named hmargin               	{               	}
+    named leftmargin            	{               	}
+    named rightmargin           	{               	}
+
+    named nodelabel			{			}
+    named nodelabelmargin		{ 0.2f			}
+    named nodelabelfont			{ -2p			}
+    named nodelabelbreak		{ ragged nohyphen	}
+    named nodelabelformat right @Body	{ @Body			}
+    import @Geometry named nodelabelpos	{ 			}
+    named nodelabelprox			{ outside		}
+    import @Geometry named nodelabelangle  { horizontal		}
+    named nodelabelctr			{ no			}
+    import @Geometry named nodelabeladjust { 0 0		}
+
+    named alabel			{			}
+    named alabelmargin			{ 			}
+    named alabelfont			{ 			}
+    named alabelbreak			{ 			}
+    named alabelformat right @Body	{ 			}
+    import @Geometry named alabelpos	{ NE			}
+    named alabelprox			{ 			}
+    import @Geometry named alabelangle	{ 			}
+    named alabelctr			{ 			}
+    import @Geometry named alabeladjust	{ 			}
+
+    named blabel			{			}
+    named blabelmargin			{ 			}
+    named blabelfont			{ 			}
+    named blabelbreak			{ 			}
+    named blabelformat right @Body	{ 			}
+    import @Geometry named blabelpos	{ NW			}
+    named blabelprox			{ 			}
+    import @Geometry named blabelangle	{ 			}
+    named blabelctr			{ 			}
+    import @Geometry named blabeladjust	{ 			}
+
+    named clabel			{			}
+    named clabelmargin			{ 			}
+    named clabelfont			{ 			}
+    named clabelbreak			{ 			}
+    named clabelformat right @Body	{ 			}
+    import @Geometry named clabelpos	{ SW			}
+    named clabelprox			{ 			}
+    import @Geometry named clabelangle	{ 			}
+    named clabelctr			{ 			}
+    import @Geometry named clabeladjust	{ 			}
+
+    named dlabel			{			}
+    named dlabelmargin			{ 			}
+    named dlabelfont			{ 			}
+    named dlabelbreak			{ 			}
+    named dlabelformat right @Body	{ 			}
+    import @Geometry named dlabelpos	{ SE			}
+    named dlabelprox			{ 			}
+    import @Geometry named dlabelangle	{ 			}
+    named dlabelctr			{ 			}
+    import @Geometry named dlabeladjust	{ 			}
+
+    import @Geometry named path
+	named from {}
+	named to {}
+	named bias {}
+	named fbias {}
+	named tbias {}
+	named radius {}
+	named xindent {}
+	named zindent {}
+	named frompt {}
+	named topt {}
+	named arrow {}
+	named arrowlength {}
+					{ line			}
+    import @Geometry named from		{ 0,0			}
+    import @Geometry named to		{ 1,1			}
+    import @Geometry named bias		{ 2.0f			}
+    import @Geometry named fbias	{ 2.0f			}
+    import @Geometry named tbias	{ 2.0f			}
+    import @Geometry named radius	{ 1.0f			}
+    import @Geometry named xindent	{ 0.8f			}
+    import @Geometry named zindent	{ 0.8f			}
+    import @Geometry named frompt	{ 0 0			}
+    import @Geometry named topt		{ 0 0			}
+    named pathstyle
+	named solid   { "/ldiagsolid"   }
+	named dashed  { "/ldiagdashed"  }
+	named cdashed { "/ldiagcdashed" }
+	named dotted  { "/ldiagdotted"  }
+	named noline  { "/ldiagnoline"  }
+					{ solid         	}
+    import @Geometry named pathdashlength { 0.2f		}
+    import @Geometry named pathwidth
+	named thin   { 0.04 ft }
+	named medium { 0.08 ft }
+	named thick  { 0.12 ft }
+					{ thin	         	}
+    import @Geometry named pathgap
+	named thin   { 0.08 ft }
+	named medium { 0.16 ft }
+	named thick  { 0.24 ft }
+					{ thin	         	}
+    named arrow                 	{ no			}
+    named arrowstyle             	{ solid			}
+    named arrowwidth             	{ 0.3f			}
+    named arrowlength            	{ 0.5f			}
+
+    named linklabel			{			}
+    named linklabelmargin		{ 0.2f			}
+    named linklabelfont			{ -2p			}
+    named linklabelbreak		{ ragged nohyphen	}
+    named linklabelformat right @Body	{ @Body			}
+    import @Geometry named linklabelpos	{ 			}
+    named linklabelprox			{ above			}
+    import @Geometry named linklabelangle  { horizontal		}
+    named linklabelctr			{ no			}
+    import @Geometry named linklabeladjust { 0 0		}
+
+    named xlabel			{			}
+    named xlabelmargin			{ 			}
+    named xlabelfont			{ 			}
+    named xlabelbreak			{ 			}
+    named xlabelformat right @Body	{ 			}
+    import @Geometry named xlabelpos	{ LFROM			}
+    named xlabelprox			{ 			}
+    import @Geometry named xlabelangle	{ 			}
+    named xlabelctr			{			}
+    import @Geometry named xlabeladjust	{ 			}
+
+    named ylabel			{			}
+    named ylabelmargin			{ 			}
+    named ylabelfont			{ 			}
+    named ylabelbreak			{ 			}
+    named ylabelformat right @Body	{ 			}
+    import @Geometry named ylabelpos	{ LMID			}
+    named ylabelprox			{ 			}
+    import @Geometry named ylabelangle	{ 			}
+    named ylabelctr			{ yes			}
+    import @Geometry named ylabeladjust	{ 			}
+
+    named zlabel			{			}
+    named zlabelmargin			{ 			}
+    named zlabelfont			{ 			}
+    named zlabelbreak			{ 			}
+    named zlabelformat right @Body	{ 			}
+    import @Geometry named zlabelpos	{ LTO			}
+    named zlabelprox			{ 			}
+    import @Geometry named zlabelangle	{ 			}
+    named zlabelctr			{			}
+    import @Geometry named zlabeladjust	{ 			}
+
+    named fromlabel			{			}
+    named fromlabelmargin		{ 0f			}
+    named fromlabelfont			{			}
+    named fromlabelbreak		{ ragged nohyphen	}
+    named fromlabelformat right @Body	{ @Body			}
+    import @Geometry named fromlabelpos	{ FROM			}
+    named fromlabelprox			{ W			}
+    import @Geometry named fromlabelangle  { antiparallel	}
+    named fromlabelctr			{ no			}
+    import @Geometry named fromlabeladjust { 0 0		}
+
+    named tolabel			{			}
+    named tolabelmargin			{ 0f			}
+    named tolabelfont			{			}
+    named tolabelbreak			{ ragged nohyphen	}
+    named tolabelformat right @Body	{ @Body			}
+    import @Geometry named tolabelpos	{ TO			}
+    named tolabelprox			{ W			}
+    import @Geometry named tolabelangle	{ parallel		}
+    named tolabelctr			{ no			}
+    import @Geometry named tolabeladjust { 0 0			}
+
+    named treehsep			{ 0.5f			}
+    named treevsep			{ 0.5f			}
+    named treehindent
+	named left  { 0.0rt }
+	named ctr   { 0.5rt }
+	named right { 1.0rt }
+					{ ctr			}
+    named treevindent
+	named top   { 0.0rt }
+	named ctr   { 0.5rt }
+	named foot  { 1.0rt }
+					{ ctr			}
+
+{
+
+    export "::" @ShowPoints @ShowTags @ShowDirections @CatchTags @Transform
+
+	   @Tree @HTree
+
+           @Node
+           @Box @CurveBox @ShadowBox @Square @Diamond @Polygon
+	   @Isosceles @Ellipse @Circle
+	   @ArrowHead @SolidArrowHead @OpenArrowHead @HalfOpenArrowHead
+	   @SolidCurvedArrowHead @OpenCurvedArrowHead @HalfOpenCurvedArrowHead
+	   @CircleArrowHead @BoxArrowHead
+
+	   @Link
+	   @Line @DoubleLine @Arrow @DoubleArrow @Curve @CurveArrow
+	   @ACurve @ACurveArrow @CCurve @CCurveArrow
+	   @Bezier @BezierArrow
+	   @HVLine @HVArrow @VHLine @VHArrow
+	   @HVCurve @HVCurveArrow @VHCurve @VHCurveArrow
+	   @LVRLine @LVRArrow @RVLLine @RVLArrow
+	   @LVRCurve @LVRCurveArrow @RVLCurve @RVLCurveArrow
+	   @DWrapLine @DWrapArrow @UWrapLine @UWrapArrow
+	   @DWrapCurve @DWrapCurveArrow @UWrapCurve @UWrapCurveArrow
+
+    def @Diag
+	named save		             	{ save	           	}
+        named maxlabels             		{ maxlabels     	}
+
+	import @Geometry named outline
+	    named margin {}
+	    named shadow {}
+	    named sides {}
+	    named angle {}
+						{ outline
+						    margin { margin }
+						    shadow { shadow }
+						    sides  { sides  }
+						    angle  { angle  }
+						}
+        named margin                		{ margin        	}
+	import @Geometry named shadow		{ shadow		}
+	import @Geometry named sides		{ sides			}
+	import @Geometry named angle		{ angle			}
+	named translate				{ translate		}
+	named nodetag				{			}
+        named outlinestyle
+	    named solid   { "/ldiagsolid"   }
+	    named dashed  { "/ldiagdashed"  }
+	    named cdashed { "/ldiagcdashed" }
+	    named dotted  { "/ldiagdotted"  }
+	    named noline  { "/ldiagnoline"  }
+						{ outlinestyle     	}
+        import @Geometry named outlinedashlength{ outlinedashlength    	}
+        import @Geometry named outlinewidth
+	    named thin   { 0.04 ft }
+	    named medium { 0.08 ft }
+	    named thick  { 0.12 ft }
+						{ outlinewidth     	}
+        named paint                 		{ paint         	}
+	named font				{ font			}
+	named break				{ break			}
+        named format right @Body    		{ format @Body  	}
+        named valign				{ valign        	}
+        named vsize                 		{ vsize         	}
+        named vindent				{ vindent       	}
+        named vstrut
+		named no  { 0.0f }
+		named yes { 1.0f }
+						{ vstrut	 	}
+        named vmargin               		{ vmargin       	}
+        named topmargin             		{ topmargin     	}
+        named footmargin            		{ footmargin    	}
+        named halign				{ halign        	}
+        named hsize                 		{ hsize         	}
+        named hindent				{ hindent       	}
+        named hstrut
+		named no  { 0.0f }
+		named yes { 1.0f }
+						{ hstrut	 	}
+        named hmargin               		{ hmargin       	}
+        named leftmargin            		{ leftmargin    	}
+        named rightmargin           		{ rightmargin   	}
+
+	import @Geometry named path
+	    named from {}
+	    named to {}
+	    named bias {}
+	    named fbias {}
+	    named tbias {}
+	    named radius {}
+	    named xindent {}
+	    named zindent {}
+	    named frompt {}
+	    named topt {}
+	    named arrow {}
+	    named arrowlength {}
+						{ path
+						    from	{ from }
+						    to		{ to   }
+						    bias	{ bias }
+						    fbias	{ fbias }
+						    tbias	{ tbias }
+						    radius	{ radius }
+						    xindent	{ xindent }
+						    zindent	{ zindent }
+						    frompt	{ frompt }
+						    topt	{ topt }
+						    arrow	{ arrow }
+						    arrowlength	{ arrowlength }
+						}
+	import @Geometry named from		{ from			}
+	import @Geometry named to		{ to			}
+	import @Geometry named bias		{ bias			}
+	import @Geometry named fbias		{ fbias			}
+	import @Geometry named tbias		{ tbias			}
+	import @Geometry named radius		{ radius		}
+	import @Geometry named xindent		{ xindent		}
+	import @Geometry named zindent		{ zindent		}
+	import @Geometry named frompt		{ frompt		}
+	import @Geometry named topt		{ topt			}
+        named pathstyle
+	    named solid   { "/ldiagsolid"   }
+	    named dashed  { "/ldiagdashed"  }
+	    named cdashed { "/ldiagcdashed" }
+	    named dotted  { "/ldiagdotted"  }
+	    named noline  { "/ldiagnoline"  }
+						{ pathstyle     	}
+        import @Geometry named pathdashlength	{ pathdashlength    	}
+        import @Geometry named pathwidth
+	    named thin   { 0.04 ft }
+	    named medium { 0.08 ft }
+	    named thick  { 0.12 ft }
+						{ pathwidth     	}
+        import @Geometry named pathgap
+	    named thin   { 0.08 ft }
+	    named medium { 0.16 ft }
+	    named thick  { 0.24 ft }
+						{ pathgap	     	}
+	named arrow				{ arrow			}
+	named arrowstyle			{ arrowstyle		}
+	named arrowwidth			{ arrowwidth		}
+	named arrowlength			{ arrowlength		}
+
+	named nodelabel				{ nodelabel		}
+	named nodelabelmargin			{ nodelabelmargin	}
+	named nodelabelfont			{ nodelabelfont		}
+	named nodelabelbreak			{ nodelabelbreak	}
+	named nodelabelformat right @Body	{ nodelabelformat @Body	}
+	import @Geometry named nodelabelpos	{ nodelabelpos		}
+	named nodelabelprox			{ nodelabelprox		}
+	import @Geometry named nodelabelangle	{ nodelabelangle	}
+	named nodelabelctr			{ nodelabelctr		}
+	import @Geometry named nodelabeladjust	{ nodelabeladjust	}
+
+        named alabel				{ alabel		}
+        named alabelmargin			{ alabelmargin		}
+        named alabelfont			{ alabelfont		}
+        named alabelbreak			{ alabelbreak		}
+	named alabelformat right @Body		{ alabelformat @Body	}
+        import @Geometry named alabelpos	{ alabelpos		}
+        named alabelprox			{ alabelprox		}
+        import @Geometry named alabelangle	{ alabelangle		}
+	named alabelctr				{ alabelctr		}
+        import @Geometry named alabeladjust	{ alabeladjust		}
+
+        named blabel				{ blabel		}
+        named blabelmargin			{ blabelmargin		}
+        named blabelfont			{ blabelfont		}
+        named blabelbreak			{ blabelbreak		}
+	named blabelformat right @Body		{ blabelformat @Body	}
+        import @Geometry named blabelpos	{ blabelpos		}
+        named blabelprox			{ blabelprox		}
+        import @Geometry named blabelangle	{ blabelangle		}
+	named blabelctr				{ blabelctr		}
+        import @Geometry named blabeladjust	{ blabeladjust		}
+
+        named clabel				{ clabel		}
+        named clabelmargin			{ clabelmargin		}
+        named clabelfont			{ clabelfont		}
+        named clabelbreak			{ clabelbreak		}
+	named clabelformat right @Body		{ clabelformat @Body	}
+        import @Geometry named clabelpos	{ clabelpos		}
+        named clabelprox			{ clabelprox		}
+        import @Geometry named clabelangle	{ clabelangle		}
+	named clabelctr				{ clabelctr		}
+        import @Geometry named clabeladjust	{ clabeladjust		}
+
+        named dlabel				{ dlabel		}
+        named dlabelmargin			{ dlabelmargin		}
+        named dlabelfont			{ dlabelfont		}
+        named dlabelbreak			{ dlabelbreak		}
+	named dlabelformat right @Body		{ dlabelformat @Body	}
+        import @Geometry named dlabelpos	{ dlabelpos		}
+        named dlabelprox			{ dlabelprox		}
+        import @Geometry named dlabelangle	{ dlabelangle		}
+	named dlabelctr				{ dlabelctr		}
+        import @Geometry named dlabeladjust	{ dlabeladjust		}
+
+        named fromlabel				{ fromlabel		}
+        named fromlabelmargin			{ fromlabelmargin	}
+        named fromlabelfont			{ fromlabelfont		}
+        named fromlabelbreak			{ fromlabelbreak	}
+	named fromlabelformat right @Body	{ fromlabelformat @Body	}
+        import @Geometry named fromlabelpos	{ fromlabelpos		}
+        named fromlabelprox			{ fromlabelprox		}
+        import @Geometry named fromlabelangle	{ fromlabelangle	}
+	named fromlabelctr			{ fromlabelctr		}
+        import @Geometry named fromlabeladjust	{ fromlabeladjust	}
+
+	named linklabel				{ linklabel		}
+	named linklabelmargin			{ linklabelmargin	}
+	named linklabelfont			{ linklabelfont		}
+	named linklabelbreak			{ linklabelbreak	}
+	named linklabelformat right @Body	{ linklabelformat @Body	}
+	import @Geometry named linklabelpos	{ linklabelpos		}
+	named linklabelprox			{ linklabelprox		}
+	import @Geometry named linklabelangle	{ linklabelangle	}
+	named linklabelctr			{ linklabelctr		}
+	import @Geometry named linklabeladjust	{ linklabeladjust	}
+
+        named xlabel				{ xlabel		}
+        named xlabelmargin			{ xlabelmargin		}
+        named xlabelfont			{ xlabelfont		}
+        named xlabelbreak			{ xlabelbreak		}
+	named xlabelformat right @Body		{ xlabelformat @Body	}
+        import @Geometry named xlabelpos	{ xlabelpos		}
+        named xlabelprox			{ xlabelprox		}
+        import @Geometry named xlabelangle	{ xlabelangle		}
+	named xlabelctr				{ xlabelctr		}
+        import @Geometry named xlabeladjust	{ xlabeladjust		}
+
+        named ylabel				{ ylabel		}
+        named ylabelmargin			{ ylabelmargin		}
+        named ylabelfont			{ ylabelfont		}
+        named ylabelbreak			{ ylabelbreak		}
+	named ylabelformat right @Body		{ ylabelformat @Body	}
+        import @Geometry named ylabelpos	{ ylabelpos		}
+        named ylabelprox			{ ylabelprox		}
+        import @Geometry named ylabelangle	{ ylabelangle		}
+	named ylabelctr				{ ylabelctr		}
+        import @Geometry named ylabeladjust	{ ylabeladjust		}
+
+        named zlabel				{ zlabel		}
+        named zlabelmargin			{ zlabelmargin		}
+        named zlabelfont			{ zlabelfont		}
+        named zlabelbreak			{ zlabelbreak		}
+	named zlabelformat right @Body		{ zlabelformat @Body	}
+        import @Geometry named zlabelpos	{ zlabelpos		}
+        named zlabelprox			{ zlabelprox		}
+        import @Geometry named zlabelangle	{ zlabelangle		}
+	named zlabelctr				{ zlabelctr		}
+        import @Geometry named zlabeladjust	{ zlabeladjust		}
+
+        named tolabel				{ tolabel		}
+        named tolabelmargin			{ tolabelmargin		}
+        named tolabelfont			{ tolabelfont		}
+        named tolabelbreak			{ tolabelbreak		}
+	named tolabelformat right @Body		{ tolabelformat @Body	}
+        import @Geometry named tolabelpos	{ tolabelpos		}
+        named tolabelprox			{ tolabelprox		}
+        import @Geometry named tolabelangle	{ tolabelangle		}
+	named tolabelctr			{ tolabelctr		}
+        import @Geometry named tolabeladjust	{ tolabeladjust		}
+
+	named treehsep				{ treehsep		}
+	named treevsep				{ treevsep		}
+	named treehindent
+	    named left  { 0.0rt }
+	    named ctr   { 0.5rt }
+	    named right { 1.0rt }
+						{ treehindent		}
+	named treevindent
+	    named top   { 0.0rt }
+	    named ctr   { 0.5rt }
+	    named foot  { 1.0rt }
+						{ treevindent		}
+        body @Body
+    @Begin
+
+        # Like @Graphic, but affects the graphics state of right parameter
+        def @InnerGraphic
+            left ps
+            right x
+        {
+          @BackEnd @Case {
+            PostScript @Yield {
+              { ps gsave // grestore } @Graphic x
+            }
+            PDF @Yield {
+              { ps q // Q } @Graphic x
+            }
+          }
+        }
+
+	def @BoxLabels right x
+	{
+          @BackEnd @Case {
+            PostScript @Yield {
+	        "[ ldiagbox ] pop" @Graphic x
+	      }
+	      PDF @Yield {}
+	    }
+	}
+
+	def @IfNonEmpty
+	    left x
+	    right y
+	{
+	    x @Case {
+		""   @Yield @Null
+		else @Yield y
+	    }
+	}
+
+	def @Else
+	    precedence 20
+	    associativity right
+	    left x
+	    right y
+	{
+	    x @Case {
+		""   @Yield y
+		else @Yield x
+	    }
+	}
+
+        def @ShowTags
+	    right x
+        {
+          @BackEnd @Case {
+            PostScript @Yield {
+            {
+	      "() ldiagpushtagdict"
+              // "ldiagshowtags ldiagpopuptagdict"
+	      } @Graphic x
+	      }
+	      PDF @Yield {}
+	    }
+        }
+
+        def @ShowPoints
+	    right x
+        {
+          @BackEnd @Case {
+            PostScript @Yield {
+            {
+	      "() ldiagpushtagdict"
+              // "ldiagshowpoints ldiagpopuptagdict"
+	      } @Graphic x
+	      }
+	      PDF @Yield {}
+	    }
+        }
+
+        def @ShowDirections
+	    right x
+        {
+          @BackEnd @Case {
+            PostScript @Yield {
+            { "() ldiagpushtagdict"
+              // "ldiagshowangles ldiagpopuptagdict" } @Graphic x
+	      }
+	      PDF @Yield {}
+	    }
+        }
+
+        def "::"
+            precedence 33
+	    associativity right
+            left name
+            right x
+        {
+          @BackEnd @Case {
+            PostScript @Yield {
+            { "("name") ldiagpushtagdict"
+              // "ldiagpopuptagdict" } @Graphic x
+	      }
+	      PDF @Yield {}
+	    }
+        }
+
+        def @CatchTags
+            precedence 33
+	    associativity right
+            right x
+        {
+          @BackEnd @Case {
+            PostScript @Yield {
+            {
+	       "() ldiagpushtagdict"
+               // "ldiagpoptagdict"
+	      }
+	      @Graphic x
+	      }
+	      PDF @Yield {}
+	    }
+        }
+
+        def @ZeroWidth right x
+        {
+	    @HContract @VContract {
+            ^|0io @HContract @VContract x |0io
+	    }
+        }
+
+        def @ZeroSize right x
+        {
+	    @HContract @VContract {
+            ^/0io ^|0io @HContract @VContract x |0io /0io
+	    }
+        }
+
+	def @FromArrowLength
+	    left arrow
+	    right arrowlength
+	{
+        @BackEnd @Case {
+          PostScript @Yield {
+	    arrow @Case {
+		{ no yes forward }   @Yield 0
+		{ back both }	     @Yield {"("arrowlength") ldiagdecodelength"}
+	    }
+	    }
+	    PDF @Yield {}
+	  }
+	}
+
+	def @ToArrowLength
+	    left arrow
+	    right arrowlength
+	{
+        @BackEnd @Case {
+          PostScript @Yield {
+	    arrow @Case {
+		{ no back }	     @Yield 0
+		{ yes forward both } @Yield {"("arrowlength") ldiagdecodelength"}
+	    }
+	    }
+	    PDF @Yield {}
+	  }
+	}
+
+	def @AddMargins
+	    named mtop {}
+	    named mfoot {}
+	    named mleft {}
+	    named mright {}
+	    right x
+	{
+
+	    @HContract @VContract {
+			 ^|mleft    |mright
+		^/mtop    |      x  |
+		 /mfoot   |         |
+	    }
+	}
+
+        def @Transform
+            precedence 32
+            import @Geometry named translate
+#               named to precedence 10 left x right y { x y "ldiagpsub" }
+                named to precedence 10 left x right y {
+                  @BackEnd @Case {
+                    PostScript @Yield { x y "ldiagpsub" }
+                    PDF @Yield {""}
+                  }
+                }
+            {}
+            import @Geometry named rotate { 0d }
+            named scale    { 1 1 }
+            right x
+        {
+          @BackEnd @Case {
+
+            PostScript @Yield {
+            { rotate "rotate" scale "scale newpath clip" }
+            @InnerGraphic
+            {
+                @ZeroSize x
+            }
+            //
+            # { rotate "rotate" scale "scale" translate "translate" }
+            { translate "translate" rotate "rotate" scale "scale" }
+            @InnerGraphic
+            {
+                @ZeroSize x
+            }
+	      }
+
+	      PDF @Yield { # presume that "rotate", "scale" and "translate" are not matrices
+            { "__cos("rotate") __sin("rotate") __sub(0, __sin("rotate")) __cos("rotate") 0 0 cm"
+              "__pick(1, "scale") 0 0 __pick(2, "scale") 0 0 cm n W" }
+            @InnerGraphic
+            {
+                @ZeroSize x
+            }
+            //
+            # { rotate "rotate" scale "scale" translate "translate" }
+            { "1 0 0 1 "translate" cm"
+              "__cos("rotate") __sin("rotate") __sub(0, __sin("rotate")) __cos("rotate") 0 0 cm"
+              "__pick(1, "scale") 0 0 __pick(2, "scale") 0 0 cm" }
+            @InnerGraphic
+            {
+                @ZeroSize x
+            }
+	      }
+
+	    }
+        }
+
+	def @DoLabel
+	    named which				{}
+	    named labeltag			{ LABEL }
+	    named label				{}
+	    named labelmargin			{}
+	    named labelfont			{}
+	    named labelbreak			{}
+	    named labelformat right @Body	{}
+	    named labelpos			{}
+	    named labelprox			{}
+	    named labelangle			{}
+	    named labelctr			{}
+	    named labeladjust			{}
+	{
+
+	    import @Geometry
+            def alignedangle
+            {
+		labelpos??"ANGLE" quadcase 
+			0	{ labelpos??"ANGLE"		}
+			0-90	{ labelpos??"ANGLE"		}
+			90	{ labelpos??"ANGLE"		}
+			90-180	{ labelpos??"ANGLE" + 180d	}
+			180	{ labelpos??"ANGLE" + 180d	}
+			180-270	{ labelpos??"ANGLE" + 180d	}
+			270	{ labelpos??"ANGLE" + 180d	}
+			270-360	{ labelpos??"ANGLE"		}
+	    }
+
+	    import @Geometry
+            def perpalignedangle
+            {
+		labelpos??"ANGLE" quadcase 
+			0	{ labelpos??"ANGLE" - 90d	}
+			0-90	{ labelpos??"ANGLE" - 90d	}
+			90	{ labelpos??"ANGLE" - 90d	}
+			90-180	{ labelpos??"ANGLE" - 90d	}
+			180	{ labelpos??"ANGLE" + 90d	}
+			180-270	{ labelpos??"ANGLE" + 90d	}
+			270	{ labelpos??"ANGLE" + 90d	}
+			270-360	{ labelpos??"ANGLE" + 90d	}
+		    
+	    }
+
+	    import @Geometry
+            def finalangle
+            {
+                labelangle @Case {
+
+		    "horizontal"	@Yield { 0d				}
+                    "aligned"		@Yield { alignedangle			}
+                    "perpendicular"	@Yield { perpalignedangle		}
+                    "parallel"		@Yield { labelpos??"ANGLE"		}
+                    "antiparallel"	@Yield { labelpos??"ANGLE" + 180d	}
+                    else		@Yield labelangle
+                }
+            }
+
+	    import @Geometry
+	    def @AlignedAboveProximity
+	    {
+		which @Case {
+		  { x f } @Yield { labelpos??ANGLE quadcase
+				0	{ (SW) }
+				0-90	{ (SW) }
+				90	{ (SW) }
+				90-180	{ (SE) }
+				180	{ (SE) }
+				180-270	{ (SE) }
+				270	{ (SE) }
+				270-360	{ (SW) }
+			  }
+		  { z t } @Yield { labelpos??ANGLE quadcase
+				0	{ (SE) }
+				0-90	{ (SE) }
+				90	{ (SE) }
+				90-180	{ (SW) }
+				180	{ (SW) }
+				180-270	{ (SW) }
+				270	{ (SW) }
+				270-360	{ (SE) }
+			  }
+		  else @Yield (S)
+		}
+	    }
+
+	    import @Geometry
+	    def @AlignedBelowProximity
+	    {
+		which @Case {
+		  { x f } @Yield { labelpos??ANGLE quadcase
+				0	{ (NW) }
+				0-90	{ (NW) }
+				90	{ (NW) }
+				90-180	{ (NE) }
+				180	{ (NE) }
+				180-270	{ (NE) }
+				270	{ (NE) }
+				270-360	{ (NW) }
+			  }
+		  { z t } @Yield { labelpos??ANGLE quadcase
+				0	{ (NE) }
+				0-90	{ (NE) }
+				90	{ (NE) }
+				90-180	{ (NW) }
+				180	{ (NW) }
+				180-270	{ (NW) }
+				270	{ (NW) }
+				270-360	{ (NE) }
+			  }
+		  else @Yield (N)
+		}
+	    }
+
+	    import @Geometry
+	    def @AlignedLeftProximity
+	    {
+		which @Case {
+		  { x f } @Yield { labelpos??ANGLE quadcase
+				0	{ (SW) }
+				0-90	{ (SW) }
+				90	{ (SW) }
+				90-180	{ (NE) }
+				180	{ (SE) }
+				180-270	{ (SE) }
+				270	{ (SE) }
+				270-360	{ (NW) }
+			  }
+		  { z t } @Yield { labelpos??ANGLE quadcase
+				0	{ (SE) }
+				0-90	{ (SE) }
+				90	{ (SE) }
+				90-180	{ (NW) }
+				180	{ (SW) }
+				180-270	{ (SW) }
+				270	{ (SW) }
+				270-360	{ (NE) }
+			  }
+		  else @Yield { labelpos??ANGLE quadcase
+				0	{ (S) }
+				0-90	{ (S) }
+				90	{ (S) }
+				90-180	{ (N) }
+				180	{ (S) }
+				180-270	{ (S) }
+				270	{ (S) }
+				270-360	{ (N) }
+			  }
+		}
+	    }
+
+	    import @Geometry
+	    def @AlignedRightProximity
+	    {
+		which @Case {
+		  { x f } @Yield { labelpos??ANGLE quadcase
+				0	{ (SW) }
+				0-90	{ (NW) }
+				90	{ (NW) }
+				90-180	{ (SE) }
+				180	{ (SE) }
+				180-270	{ (NE) }
+				270	{ (NE) }
+				270-360	{ (SW) }
+			  }
+		  { z t } @Yield { labelpos??ANGLE quadcase
+				0	{ (SE) }
+				0-90	{ (NE) }
+				90	{ (NE) }
+				90-180	{ (SW) }
+				180	{ (SW) }
+				180-270	{ (NW) }
+				270	{ (NW) }
+				270-360	{ (SE) }
+			  }
+		  else @Yield { labelpos??ANGLE quadcase
+				0	{ (S) }
+				0-90	{ (N) }
+				90	{ (N) }
+				90-180	{ (S) }
+				180	{ (S) }
+				180-270	{ (N) }
+				270	{ (N) }
+				270-360	{ (S) }
+			  }
+		}
+	    }
+
+	    import @Geometry
+	    def @AlignedInsideProximity
+	    {
+		which @Case {
+		  { x f } @Yield { labelpos??ANGLE quadcase
+				0	{ (SW) }
+				0-90	{ (SW) }
+				90	{ (SW) }
+				90-180	{ (NE) }
+				180	{ (NE) }
+				180-270	{ (NE) }
+				270	{ (NE) }
+				270-360	{ (SW) }
+			  }
+		  { z t } @Yield { labelpos??ANGLE quadcase
+				0	{ (SE) }
+				0-90	{ (SE) }
+				90	{ (SE) }
+				90-180	{ (NW) }
+				180	{ (NW) }
+				180-270	{ (NW) }
+				270	{ (NW) }
+				270-360	{ (SE) }
+			  }
+		  else @Yield { labelpos??ANGLE quadcase
+				0	{ (S) }
+				0-90	{ (S) }
+				90	{ (S) }
+				90-180	{ (N) }
+				180	{ (N) }
+				180-270	{ (N) }
+				270	{ (N) }
+				270-360	{ (S) }
+			  }
+		}
+	    }
+
+	    import @Geometry
+	    def @AlignedOutsideProximity
+	    {
+		which @Case {
+		  { x f } @Yield { labelpos??ANGLE quadcase
+				0	{ (NW) }
+				0-90	{ (NW) }
+				90	{ (NW) }
+				90-180	{ (SE) }
+				180	{ (SE) }
+				180-270	{ (SE) }
+				270	{ (SE) }
+				270-360	{ (NW) }
+			  }
+		  { z t } @Yield { labelpos??ANGLE quadcase
+				0	{ (NE) }
+				0-90	{ (NE) }
+				90	{ (NE) }
+				90-180	{ (SW) }
+				180	{ (SW) }
+				180-270	{ (SW) }
+				270	{ (SW) }
+				270-360	{ (NE) }
+			  }
+		  else @Yield { labelpos??ANGLE quadcase
+				0	{ (N) }
+				0-90	{ (N) }
+				90	{ (N) }
+				90-180	{ (S) }
+				180	{ (S) }
+				180-270	{ (S) }
+				270	{ (S) }
+				270-360	{ (N) }
+			  }
+		}
+	    }
+
+
+	    import @Geometry
+	    def @PerpendicularAboveProximity
+	    {
+		which @Case {
+		  { x f } @Yield { labelpos??ANGLE quadcase
+				0	{ (SE) }
+				0-90	{ (SE) }
+				90	{ (SE) }
+				90-180	{ (SW) }
+				180	{ (NE) }
+				180-270	{ (NE) }
+				270	{ (NE) }
+				270-360	{ (NW) }
+			  }
+		  { z t } @Yield { labelpos??ANGLE quadcase
+				0	{ (NE) }
+				0-90	{ (NE) }
+				90	{ (NE) }
+				90-180	{ (NW) }
+				180	{ (SE) }
+				180-270	{ (SE) }
+				270	{ (SE) }
+				270-360	{ (SW) }
+			  }
+		  else @Yield { labelpos??ANGLE quadcase
+				0	{ (E) }
+				0-90	{ (E) }
+				90	{ (E) }
+				90-180	{ (W) }
+				180	{ (E) }
+				180-270	{ (E) }
+				270	{ (E) }
+				270-360	{ (W) }
+			  }
+		}
+	    }
+
+	    import @Geometry
+	    def @PerpendicularBelowProximity
+	    {
+		which @Case {
+		  { x f } @Yield { labelpos??ANGLE quadcase
+				0	{ (SW) }
+				0-90	{ (SW) }
+				90	{ (SW) }
+				90-180	{ (SE) }
+				180	{ (NW) }
+				180-270	{ (NW) }
+				270	{ (NW) }
+				270-360	{ (NE) }
+			  }
+		  { z t } @Yield { labelpos??ANGLE quadcase
+				0	{ (NW) }
+				0-90	{ (NW) }
+				90	{ (NW) }
+				90-180	{ (NE) }
+				180	{ (SW) }
+				180-270	{ (SW) }
+				270	{ (SW) }
+				270-360	{ (SE) }
+			  }
+		  else @Yield { labelpos??ANGLE quadcase
+				0	{ (W) }
+				0-90	{ (W) }
+				90	{ (W) }
+				90-180	{ (E) }
+				180	{ (W) }
+				180-270	{ (W) }
+				270	{ (W) }
+				270-360	{ (E) }
+			  }
+		}
+	    }
+
+	    import @Geometry
+	    def @PerpendicularLeftProximity
+	    {
+		which @Case {
+		  { x f } @Yield { labelpos??ANGLE quadcase
+				0	{ (SE) }
+				0-90	{ (SE) }
+				90	{ (SE) }
+				90-180	{ (SE) }
+				180	{ (NE) }
+				180-270	{ (NE) }
+				270	{ (NE) }
+				270-360	{ (NE) }
+			  }
+		  { z t } @Yield { labelpos??ANGLE quadcase
+				0	{ (NE) }
+				0-90	{ (NE) }
+				90	{ (NE) }
+				90-180	{ (NE) }
+				180	{ (SE) }
+				180-270	{ (SE) }
+				270	{ (SE) }
+				270-360	{ (SE) }
+			  }
+		  else @Yield (E)
+		}
+	    }
+
+	    import @Geometry
+	    def @PerpendicularRightProximity
+	    {
+		which @Case {
+		  { x f } @Yield { labelpos??ANGLE quadcase
+				0	{ (SW) }
+				0-90	{ (SW) }
+				90	{ (SW) }
+				90-180	{ (SW) }
+				180	{ (NW) }
+				180-270	{ (NW) }
+				270	{ (NW) }
+				270-360	{ (NW) }
+			  }
+		  { z t } @Yield { labelpos??ANGLE quadcase
+				0	{ (NW) }
+				0-90	{ (NW) }
+				90	{ (NW) }
+				90-180	{ (NW) }
+				180	{ (SW) }
+				180-270	{ (SW) }
+				270	{ (SW) }
+				270-360	{ (SW) }
+			  }
+		  else @Yield (W)
+		}
+	    }
+
+	    import @Geometry
+	    def @PerpendicularInsideProximity
+	    {
+		which @Case {
+		  { x f } @Yield { labelpos??ANGLE quadcase
+				0	{ (SE) }
+				0-90	{ (SE) }
+				90	{ (SE) }
+				90-180	{ (SE) }
+				180	{ (NW) }
+				180-270	{ (NW) }
+				270	{ (NW) }
+				270-360	{ (NW) }
+			  }
+		  { z t } @Yield { labelpos??ANGLE quadcase
+				0	{ (NE) }
+				0-90	{ (NE) }
+				90	{ (NE) }
+				90-180	{ (NE) }
+				180	{ (SW) }
+				180-270	{ (SW) }
+				270	{ (SW) }
+				270-360	{ (SW) }
+			  }
+		  else @Yield { labelpos??ANGLE quadcase
+				0	{ (E) }
+				0-90	{ (E) }
+				90	{ (E) }
+				90-180	{ (E) }
+				180	{ (W) }
+				180-270	{ (W) }
+				270	{ (W) }
+				270-360	{ (W) }
+			  }
+		}
+	    }
+
+	    import @Geometry
+	    def @PerpendicularOutsideProximity
+	    {
+		which @Case {
+		  { x f } @Yield { labelpos??ANGLE quadcase
+				0	{ (SW) }
+				0-90	{ (SW) }
+				90	{ (SW) }
+				90-180	{ (SW) }
+				180	{ (NE) }
+				180-270	{ (NE) }
+				270	{ (NE) }
+				270-360	{ (NE) }
+			  }
+		  { z t } @Yield { labelpos??ANGLE quadcase
+				0	{ (NW) }
+				0-90	{ (NW) }
+				90	{ (NW) }
+				90-180	{ (NW) }
+				180	{ (SE) }
+				180-270	{ (SE) }
+				270	{ (SE) }
+				270-360	{ (SE) }
+			  }
+		  else @Yield { labelpos??ANGLE quadcase
+				0	{ (W) }
+				0-90	{ (W) }
+				90	{ (W) }
+				90-180	{ (W) }
+				180	{ (E) }
+				180-270	{ (E) }
+				270	{ (E) }
+				270-360	{ (E) }
+			  }
+		}
+	    }
+
+
+	    import @Geometry
+	    def @OtherAboveProximity
+	    {
+		which @Case {
+		  { x f } @Yield { labelpos??ANGLE quadcase
+				0	{ (SW) }
+				0-90	{ (SE) }
+				90	{ (SW) }
+				90-180	{ (SW) }
+				180	{ (SE) }
+				180-270	{ (SE) }
+				270	{ (NW) }
+				270-360	{ (SW) }
+			  }
+		  { z t } @Yield { labelpos??ANGLE quadcase
+				0	{ (SE) }
+				0-90	{ (SE) }
+				90	{ (NW) }
+				90-180	{ (SW) }
+				180	{ (SW) }
+				180-270	{ (SE) }
+				270	{ (SW) }
+				270-360	{ (SW) }
+			  }
+		  else @Yield { labelpos??ANGLE quadcase
+				0	{ (S) }
+				0-90	{ (SE) }
+				90	{ (W) }
+				90-180	{ (SW) }
+				180	{ (S) }
+				180-270	{ (SE) }
+				270	{ (W) }
+				270-360	{ (SW) }
+			  }
+		}
+	    }
+
+	    import @Geometry
+	    def @OtherBelowProximity
+	    {
+		which @Case {
+		  { x f } @Yield { labelpos??ANGLE quadcase
+				0	{ (NW) }
+				0-90	{ (NW) }
+				90	{ (SW) }
+				90-180	{ (NE) }
+				180	{ (NE) }
+				180-270	{ (NW) }
+				270	{ (NW) }
+				270-360	{ (NE) }
+			  }
+		  { z t } @Yield { labelpos??ANGLE quadcase
+				0	{ (NE) }
+				0-90	{ (NW) }
+				90	{ (NW) }
+				90-180	{ (NE) }
+				180	{ (NW) }
+				180-270	{ (NW) }
+				270	{ (SW) }
+				270-360	{ (NE) }
+			  }
+		  else @Yield { labelpos??ANGLE quadcase
+				0	{ (N) }
+				0-90	{ (NW) }
+				90	{ (W) }
+				90-180	{ (NE) }
+				180	{ (N) }
+				180-270	{ (NW) }
+				270	{ (W) }
+				270-360	{ (NE) }
+			  }
+		}
+	    }
+
+	    import @Geometry
+	    def @OtherLeftProximity
+	    {
+		which @Case {
+		  { x f } @Yield { labelpos??ANGLE quadcase
+				0	{ (SW) }
+				0-90	{ (SE) }
+				90	{ (SE) }
+				90-180	{ (NE) }
+				180	{ (SE) }
+				180-270	{ (SE) }
+				270	{ (NE) }
+				270-360	{ (NE) }
+			  }
+		  { z t } @Yield { labelpos??ANGLE quadcase
+				0	{ (SE) }
+				0-90	{ (SE) }
+				90	{ (NE) }
+				90-180	{ (NE) }
+				180	{ (SW) }
+				180-270	{ (SE) }
+				270	{ (SE) }
+				270-360	{ (NE) }
+			  }
+		  else @Yield { labelpos??ANGLE quadcase
+				0	{ (S) }
+				0-90	{ (SE) }
+				90	{ (E) }
+				90-180	{ (NE) }
+				180	{ (S) }
+				180-270	{ (SE) }
+				270	{ (E) }
+				270-360	{ (NE) }
+			  }
+		}
+	    }
+
+	    import @Geometry
+	    def @OtherRightProximity
+	    {
+		which @Case {
+		  { x f } @Yield { labelpos??ANGLE quadcase
+				0	{ (SW) }
+				0-90	{ (NW) }
+				90	{ (SW) }
+				90-180	{ (SW) }
+				180	{ (SE) }
+				180-270	{ (NW) }
+				270	{ (NW) }
+				270-360	{ (SW) }
+			  }
+		  { z t } @Yield { labelpos??ANGLE quadcase
+				0	{ (SE) }
+				0-90	{ (NW) }
+				90	{ (NW) }
+				90-180	{ (SW) }
+				180	{ (SW) }
+				180-270	{ (NW) }
+				270	{ (SW) }
+				270-360	{ (SW) }
+			  }
+		  else @Yield { labelpos??ANGLE quadcase
+				0	{ (S) }
+				0-90	{ (NW) }
+				90	{ (W) }
+				90-180	{ (SW) }
+				180	{ (S) }
+				180-270	{ (NW) }
+				270	{ (W) }
+				270-360	{ (SW) }
+			  }
+		}
+	    }
+
+	    import @Geometry
+	    def @OtherInsideProximity
+	    {
+		which @Case {
+		  { x f } @Yield { labelpos??ANGLE quadcase
+				0	{ (SW) }
+				0-90	{ (SE) }
+				90	{ (SE) }
+				90-180	{ (NE) }
+				180	{ (NE) }
+				180-270	{ (NW) }
+				270	{ (NW) }
+				270-360	{ (SW) }
+			  }
+		  { z t } @Yield { labelpos??ANGLE quadcase
+				0	{ (SE) }
+				0-90	{ (SE) }
+				90	{ (NE) }
+				90-180	{ (NE) }
+				180	{ (NW) }
+				180-270	{ (NW) }
+				270	{ (SW) }
+				270-360	{ (SW) }
+			  }
+		  else @Yield { labelpos??ANGLE quadcase
+				0	{ (S) }
+				0-90	{ (SE) }
+				90	{ (E) }
+				90-180	{ (NE) }
+				180	{ (N) }
+				180-270	{ (NW) }
+				270	{ (W) }
+				270-360	{ (SW) }
+			  }
+		}
+	    }
+
+	    import @Geometry
+	    def @OtherOutsideProximity
+	    {
+		which @Case {
+		  { x f } @Yield { labelpos??ANGLE quadcase
+				0	{ (NW) }
+				0-90	{ (NW) }
+				90	{ (SW) }
+				90-180	{ (SW) }
+				180	{ (SE) }
+				180-270	{ (SE) }
+				270	{ (NE) }
+				270-360	{ (NE) }
+			  }
+		  { z t } @Yield { labelpos??ANGLE quadcase
+				0	{ (NE) }
+				0-90	{ (NW) }
+				90	{ (NW) }
+				90-180	{ (SW) }
+				180	{ (SW) }
+				180-270	{ (SE) }
+				270	{ (SE) }
+				270-360	{ (NE) }
+			  }
+		  else @Yield { labelpos??ANGLE quadcase
+				0	{ (N) }
+				0-90	{ (NW) }
+				90	{ (W) }
+				90-180	{ (SW) }
+				180	{ (S) }
+				180-270	{ (SE) }
+				270	{ (E) }
+				270-360	{ (NE) }
+			  }
+		}
+	    }
+
+
+	    import @Geometry
+	    def @AboveProximity
+	    {
+                labelangle @Case {
+                    "aligned"		@Yield @AlignedAboveProximity
+		    "perpendicular"	@Yield @PerpendicularAboveProximity
+                    else		@Yield @OtherAboveProximity
+                }
+	    }
+
+	    import @Geometry
+	    def @BelowProximity
+	    {
+                labelangle @Case {
+                    "aligned"		@Yield @AlignedBelowProximity
+		    "perpendicular"	@Yield @PerpendicularBelowProximity
+                    else		@Yield @OtherBelowProximity
+                }
+	    }
+
+	    import @Geometry
+	    def @LeftProximity
+	    {
+                labelangle @Case {
+                    "aligned"		@Yield @AlignedLeftProximity
+		    "perpendicular"	@Yield @PerpendicularLeftProximity
+                    else		@Yield @OtherLeftProximity
+                }
+	    }
+
+	    import @Geometry
+	    def @RightProximity
+	    {
+                labelangle @Case {
+                    "aligned"		@Yield @AlignedRightProximity
+		    "perpendicular"	@Yield @PerpendicularRightProximity
+                    else		@Yield @OtherRightProximity
+                }
+	    }
+
+	    import @Geometry
+	    def @InsideProximity
+	    {
+                labelangle @Case {
+                    "aligned"		@Yield @AlignedInsideProximity
+		    "perpendicular"	@Yield @PerpendicularInsideProximity
+                    else		@Yield @OtherInsideProximity
+                }
+	    }
+
+	    import @Geometry
+	    def @OutsideProximity
+	    {
+                labelangle @Case {
+                    "aligned"		@Yield @AlignedOutsideProximity
+		    "perpendicular"	@Yield @PerpendicularOutsideProximity
+                    else		@Yield @OtherOutsideProximity
+                }
+	    }
+
+	    import @Geometry
+            def proximity
+            {
+                labelprox @Case {
+                    above   @Yield @AboveProximity
+                    below   @Yield @BelowProximity
+                    left    @Yield @LeftProximity
+                    right   @Yield @RightProximity
+                    inside  @Yield @InsideProximity
+                    outside @Yield @OutsideProximity
+		    else    @Yield { "("labelprox")" }
+                }
+            }
+
+	    import @Geometry
+	    def dorotate
+		left point
+		right angle
+	    {
+		{ {0 0} distance point } atangle { {0 0} angleto point + angle }
+	    }
+
+	    import @Geometry
+	    def translation
+	    {
+		labelctr @Case {
+		    { no No } @Yield {
+			labelpos -- labeltag?!?proximity
+		    }
+		    { yes Yes } @Yield {
+			#P0	:= labelpos
+			#P1	:= labeltag?!?proximity -- P0
+			#P2	:= labeltag??CTR -- P0
+			#TH	:= labelpos??ANGLE
+			#P1A	:= P1 dorotate { 0 - TH }
+			#P2A	:= P2 dorotate { 0 - TH }
+			#PRA	:= { 0 - xcoord P2A 0 - ycoord P1A }
+			#PRA dorotate TH ++ P0
+			XP1	:= labeltag?!?proximity
+			XP2	:= labeltag??CTR
+			XANG	:= labelpos??ANGLE
+			XTH	:= XANG - 90d - { XP1 angleto XP2 }
+			XDIST	:= { XP1 distance XP2 } * sin XTH
+			labelpos -- XP1 ++ XDIST atangle XANG
+		    }
+		}
+	    }
+
+	    @CatchTags @ZeroSize @Transform
+		translate { translation ++ labeladjust }
+		rotate { finalangle }
+		scale { 1 1 }
+	    labeltag:: @BoxLabels @CatchTags @AddMargins
+		mtop { labelmargin }
+		mfoot { labelmargin }
+		mleft { labelmargin }
+		mright { labelmargin }
+	    labelfont @Font labelbreak @Break labelformat label
+	}
+
+
+        def @Node
+            import @Geometry named translate
+#               named to precedence 10 left x right y { x y "ldiagpsub" }
+                named to precedence 10 left x right y {
+                  @BackEnd @Case {
+                    PostScript @Yield { x y "ldiagpsub" }
+                    PDF @Yield {""}
+                  }
+                }
+            {}
+            import @Geometry named rotate	{ 0d			}
+	    import @Geometry named outline
+		named margin {}
+		named shadow {}
+		named sides {}
+		named angle {}
+						{ outline
+						    margin { margin }
+						    shadow { shadow }
+						    sides  { sides  }
+						    angle  { angle  }
+						}
+	    named margin               		{ margin        	}
+	    import @Geometry named shadow	{ shadow		}
+	    import @Geometry named sides	{ sides			}
+	    import @Geometry named angle	{ angle			}
+	    named nodetag			{ nodetag		}
+            named outlinestyle
+		named solid   { "/ldiagsolid"   }
+		named dashed  { "/ldiagdashed"  }
+		named cdashed { "/ldiagcdashed" }
+		named dotted  { "/ldiagdotted"  }
+		named noline  { "/ldiagnoline"  }
+						{ outlinestyle     	}
+            import @Geometry named outlinedashlength { outlinedashlength}
+            import @Geometry named outlinewidth
+		named thin   { 0.04 ft }
+		named medium { 0.08 ft }
+		named thick  { 0.12 ft }
+						{ outlinewidth     	}
+            named paint				{ paint         	}
+	    named font				{ font			}
+	    named break				{ break			}
+            named format right @Body		{ format @Body  	}
+            named valign			{ valign        	}
+            named vsize				{ vsize         	}
+            named vindent			{ vindent       	}
+	    named vstrut
+		named no  { 0.0f }
+		named yes { 1.0f }
+						{ vstrut	 	}
+            named vmargin			{ vmargin       	}
+            named topmargin			{ topmargin     	}
+            named footmargin			{ footmargin    	}
+
+            named halign			{ halign        	}
+            named hsize				{ hsize         	}
+            named hindent			{ hindent       	}
+	    named hstrut
+		named no  { 0.0f }
+		named yes { 1.0f }
+						{ hstrut	 	}
+            named hmargin			{ hmargin       	}
+            named leftmargin			{ leftmargin    	}
+            named rightmargin			{ rightmargin   	}
+
+	    named nodelabel			{ nodelabel		}
+	    named nodelabelmargin		{ nodelabelmargin	}
+	    named nodelabelfont			{ nodelabelfont		}
+	    named nodelabelbreak		{ nodelabelbreak	}
+	    named nodelabelformat right @Body	{ nodelabelformat @Body	}
+	    import @Geometry named nodelabelpos	{ nodelabelpos		}
+	    named nodelabelprox			{ nodelabelprox		}
+	    import @Geometry named nodelabelangle  { nodelabelangle	}
+	    named nodelabelctr			{ nodelabelctr		}
+	    import @Geometry named nodelabeladjust { nodelabeladjust	}
+
+            named alabel			{ alabel		}
+            named alabelmargin			{ alabelmargin		}
+            named alabelfont			{ alabelfont		}
+            named alabelbreak			{ alabelbreak		}
+	    named alabelformat right @Body	{ alabelformat @Body	}
+            import @Geometry named alabelpos	{ alabelpos		}
+            named alabelprox			{ alabelprox		}
+            import @Geometry named alabelangle	{ alabelangle		}
+	    named alabelctr			{ alabelctr		}
+            import @Geometry named alabeladjust	{ alabeladjust		}
+
+            named blabel			{ blabel		}
+            named blabelmargin			{ blabelmargin		}
+            named blabelfont			{ blabelfont		}
+            named blabelbreak			{ blabelbreak		}
+	    named blabelformat right @Body	{ blabelformat @Body	}
+            import @Geometry named blabelpos	{ blabelpos		}
+            named blabelprox			{ blabelprox		}
+            import @Geometry named blabelangle	{ blabelangle		}
+	    named blabelctr			{ blabelctr		}
+            import @Geometry named blabeladjust	{ blabeladjust		}
+
+            named clabel			{ clabel		}
+            named clabelmargin			{ clabelmargin		}
+            named clabelfont			{ clabelfont		}
+            named clabelbreak			{ clabelbreak		}
+	    named clabelformat right @Body	{ clabelformat @Body	}
+            import @Geometry named clabelpos	{ clabelpos		}
+            named clabelprox			{ clabelprox		}
+            import @Geometry named clabelangle	{ clabelangle		}
+	    named clabelctr			{ clabelctr		}
+            import @Geometry named clabeladjust	{ clabeladjust		}
+
+            named dlabel			{ dlabel		}
+            named dlabelmargin			{ dlabelmargin		}
+            named dlabelfont			{ dlabelfont		}
+            named dlabelbreak			{ dlabelbreak		}
+	    named dlabelformat right @Body	{ dlabelformat @Body	}
+            import @Geometry named dlabelpos	{ dlabelpos		}
+            named dlabelprox			{ dlabelprox		}
+            import @Geometry named dlabelangle	{ dlabelangle		}
+	    named dlabelctr			{ dlabelctr		}
+            import @Geometry named dlabeladjust	{ dlabeladjust		}
+
+            right @Body
+        {
+
+            def @LabelPos
+		left x
+		right y
+            {
+		nodelabelpos @Case {
+		    x    @Yield y
+		    else @Yield ""
+		}
+            }
+
+            def @If
+		left cond
+		right x
+            {
+		cond @Case {
+		    { yes Yes } @Yield x
+		    else        @Yield ""
+		}
+            }
+
+
+            def @Strut right x
+            {
+		def vs { 0.5w @VShift { vstrut @High } }
+		def hs {                hstrut @Wide   }
+
+		@HContract @VContract {
+		    @HContract @VContract x | vs / hs |
+		}
+            }
+
+	    def @Indent right x
+	    {
+		x @Case {
+		    { top left   } @Yield 0.0rt
+		    { ctr        } @Yield 0.5rt
+		    { foot right } @Yield 1.0rt
+		    { mctr	     } @Yield 0.5bx
+		    else           @Yield x
+		}
+	    }
+
+            def @VSize right x
+            {
+		vsize @Case {
+		    ""   @Yield x
+		    else @Yield { vsize @High { /{@Indent vindent} x / } }
+		}
+            }
+
+            def @HSize right x
+            {
+		hsize @Case {
+		    ""   @Yield x
+		    else @Yield { hsize @Wide { |{@Indent hindent} x | } }
+		}
+            }
+
+	    def @Align right x
+	    {
+		x @Case {
+		    { top left   } @Yield 0.0w
+		    { ctr        } @Yield 0.5w
+		    { foot right } @Yield 1.0w
+		    { mark       } @Yield "+0i"
+		    else           @Yield x
+		}
+	    }
+
+	    def @ALabel
+	    {
+		@DoLabel
+		    which	{ "a"						}
+		    label	{ alabel	     @Else nodelabel		}
+		    labelmargin	{ alabelmargin	     @Else nodelabelmargin	}
+		    labelfont	{ alabelfont	     @Else nodelabelfont	}
+		    labelbreak	{ alabelbreak	     @Else nodelabelbreak	}
+		    labelformat { alabelformat @Body @Else nodelabelformat @Body}
+		    labelpos	{ alabelpos	     @Else nodelabelpos		}
+		    labelprox	{ alabelprox	     @Else nodelabelprox	}
+		    labelangle	{ alabelangle	     @Else nodelabelangle	}
+		    labelctr	{ alabelctr	     @Else nodelabelctr		}
+		    labeladjust	{ alabeladjust	     @Else nodelabeladjust	}
+	    }
+
+	    def @BLabel
+	    {
+		@DoLabel
+		    which	{ "b"						}
+		    label	{ blabel	     @Else nodelabel		}
+		    labelmargin	{ blabelmargin	     @Else nodelabelmargin	}
+		    labelfont	{ blabelfont	     @Else nodelabelfont	}
+		    labelbreak	{ blabelbreak	     @Else nodelabelbreak	}
+		    labelformat { blabelformat @Body @Else nodelabelformat @Body}
+		    labelpos	{ blabelpos	     @Else nodelabelpos		}
+		    labelprox	{ blabelprox	     @Else nodelabelprox	}
+		    labelangle	{ blabelangle	     @Else nodelabelangle	}
+		    labelctr	{ blabelctr	     @Else nodelabelctr		}
+		    labeladjust	{ blabeladjust	     @Else nodelabeladjust	}
+	    }
+
+	    def @CLabel
+	    {
+		@DoLabel
+		    which	{ "c"						}
+		    label	{ clabel	     @Else nodelabel		}
+		    labelmargin	{ clabelmargin	     @Else nodelabelmargin	}
+		    labelfont	{ clabelfont	     @Else nodelabelfont	}
+		    labelbreak	{ clabelbreak	     @Else nodelabelbreak	}
+		    labelformat { clabelformat @Body @Else nodelabelformat @Body}
+		    labelpos	{ clabelpos	     @Else nodelabelpos		}
+		    labelprox	{ clabelprox	     @Else nodelabelprox	}
+		    labelangle	{ clabelangle	     @Else nodelabelangle	}
+		    labelctr	{ clabelctr	     @Else nodelabelctr		}
+		    labeladjust	{ clabeladjust	     @Else nodelabeladjust	}
+	    }
+
+	    def @DLabel
+	    {
+		@DoLabel
+		    which	{ "d"						}
+		    label	{ dlabel	     @Else nodelabel		}
+		    labelmargin	{ dlabelmargin	     @Else nodelabelmargin	}
+		    labelfont	{ dlabelfont	     @Else nodelabelfont	}
+		    labelbreak	{ dlabelbreak	     @Else nodelabelbreak	}
+		    labelformat { dlabelformat @Body @Else nodelabelformat @Body}
+		    labelpos	{ dlabelpos	     @Else nodelabelpos		}
+		    labelprox	{ dlabelprox	     @Else nodelabelprox	}
+		    labelangle	{ dlabelangle	     @Else nodelabelangle	}
+		    labelctr	{ dlabelctr	     @Else nodelabelctr		}
+		    labeladjust	{ dlabeladjust	     @Else nodelabeladjust	}
+	    }
+
+	    import @Geometry
+	    def @OutLine
+	    {
+	      @BackEnd @Case {
+	        PostScript @Yield {
+		outline @Case {
+		    box		@Yield { "ldiagbox"			}
+		    curvebox	@Yield { "("margin") ldiagcurvebox"	}
+		    shadowbox	@Yield { shadow "ldiagshadow ldiagbox"	}
+		    square	@Yield { "ldiagsquare"			}
+		    diamond	@Yield { "ldiagdiamond"			}
+		    polygon	@Yield { sides angle "ldiagpolygon"	}
+		    isosceles	@Yield { "ldiagisosceles"		}
+		    ellipse	@Yield { "ldiagellipse"			}
+		    circle	@Yield { "ldiagcircle"			}
+		    else	    @Yield {
+				    outline
+					margin { "("margin") ldiagdecodelength" }
+					shadow { shadow }
+					sides  { sides  }
+					angle  { angle  }
+		    }
+		}
+		  }
+		  PDF @Yield {}
+		}
+	    }
+
+	    def @Value
+            {
+              @BackEnd @Case {
+                PostScript @Yield {
+		@HContract @VContract
+		{
+		    {
+			"ldiagnodebegin [" @OutLine "]"
+			outlinedashlength "[" outlinestyle "]"
+			outlinewidth "/ldiag"paint "ldiagnodeend"
+			"(IN) ldiagpushtagdict"
+			//
+			"ldiagpopuptagdict"
+		    }
+		    @Graphic
+		    {
+			{@Align valign} @VShift {@Align halign} @HShift
+			@AddMargins
+			    mtop   { topmargin   @Else vmargin @Else margin }
+			    mfoot  { footmargin  @Else vmargin @Else margin }
+			    mleft  { leftmargin  @Else hmargin @Else margin }
+			    mright { rightmargin @Else hmargin @Else margin }
+			    @HSize @VSize @HContract @VContract
+			    font @Font break @Break format @Strut @Body
+		    }
+		    / {alabel @Else nodelabel} @IfNonEmpty @ALabel
+		    / {blabel @Else nodelabel} @IfNonEmpty @BLabel
+		    / {clabel @Else nodelabel} @IfNonEmpty @CLabel
+		    / {dlabel @Else nodelabel} @IfNonEmpty @DLabel
+		}
+                }
+                PDF @Yield {}
+              }
+            }
+
+	    def @TValue
+	    {
+		nodetag @Case {
+		    ""   @Yield @Value
+		    else @Yield { nodetag:: @Value }
+		}
+	    }
+
+            translate @Case {
+                  "" @Yield @TValue
+                  else @Yield {
+		    @Null & # so that preceding space gets chewed up
+                    @Transform translate { translate } rotate { rotate } @TValue
+                  }
+            }
+        }
+
+	macro @@Node	 { @Node			  }
+        macro @Box	 { @Node outline { box		} }
+        macro @CurveBox	 { @Node outline { curvebox	} }
+	macro @ShadowBox { @Node outline { shadowbox	} }
+        macro @Square	 { @Node outline { square	} }
+        macro @Diamond	 { @Node outline { diamond	} }
+        macro @Polygon	 { @Node outline { polygon	} }
+        macro @Isosceles { @Node outline { isosceles	} }
+        macro @Ellipse	 { @Node outline { ellipse	} }
+        macro @Circle	 { @Node outline { circle	} }
+
+
+	macro @InsulatedNode {
+	    @Node
+		topmargin { 0i }
+		footmargin { 0i }
+		leftmargin { 0i }
+		rightmargin { 0i }
+		alabel {}
+		blabel {}
+		clabel {}
+		dlabel {}
+		hsize {}
+		vsize {}
+		vstrut { no }
+		hstrut { no }
+	}
+
+	def @SolidArrowHead
+	    named width { arrowwidth }
+	    named length { arrowlength }
+	    named pathwidth { pathwidth }
+	{
+	    @InsulatedNode
+		paint { nochange }
+		outlinestyle { noline }
+		outlinewidth { pathwidth }
+		outline {
+		  @BackEnd @Case {
+		    PostScript @Yield {
+		    "ldiagsolidarrowhead"
+		    # 0 0 xsize ysize * 0.5 0 ysize
+		    }
+		    PDF @Yield {}
+		  }
+		}
+	    {
+		length @Wide width @High
+	    }
+	}
+
+	def @OpenArrowHead
+	    named width { arrowwidth }
+	    named length { arrowlength }
+	    named pathwidth { pathwidth }
+	{
+	    @InsulatedNode
+		outlinewidth { pathwidth }
+		outlinestyle { noline }
+		paint { nochange }
+		outline {
+		  @BackEnd @Case {
+		    PostScript @Yield {
+		    pathwidth "ldiagopenarrowhead"
+
+		    # PSW := { 0 0 }
+		    # PNW := { 0 ysize }
+		    # PE  := { xsize ysize*0.5 }
+		    # REL := pathwidth atangle { PE angleto PNW + 90d }
+		    # PNA := { 0 ysize*0.5 + pathwidth*0.5 }
+		    # PSA := { 0 ysize*0.5 - pathwidth*0.5 }
+		    # PNI := {
+		    #   PNA PNA ++ { xsize 0 }
+		    #   PNW ++ REL PE ++ REL ldiaglineintersect
+		    # }
+		    # PSI := PNI -- { 0 pathwidth }
+		    #
+		    # PSW PE PNW PNI PNA PSA PSI PSW
+		    }
+		    PDF @Yield {}
+		  }
+		}
+	    {
+		length @Wide width @High
+	    }
+	}
+
+	def @HalfOpenArrowHead
+	    named width { arrowwidth }
+	    named length { arrowlength }
+	    named pathwidth { pathwidth }
+	{
+	    @InsulatedNode
+		paint { nochange }
+		outlinestyle { noline }
+		outlinewidth { pathwidth }
+		outline {
+		  @BackEnd @Case {
+		    PostScript @Yield {
+		    pathwidth "ldiaghalfopenarrowhead"
+
+		    # 0 0
+		    # xsize ysize * 0.5
+		    # 0 ysize
+		    # xsize*0.3 ysize*0.5 + pathwidth*0.5
+		    # 0         ysize*0.5 + pathwidth*0.5
+		    # 0         ysize*0.5 - pathwidth*0.5
+		    # xsize*0.3 ysize*0.5 - pathwidth*0.5
+		    # 0 0
+		    }
+		    PDF @Yield {}
+		  }
+		}
+	    {
+		length @Wide width @High
+	    }
+	}
+
+	def @SolidCurvedArrowHead
+	    named width { arrowwidth }
+	    named length { arrowlength }
+	    named pathwidth { pathwidth }
+	{
+	    @InsulatedNode
+		outlinestyle { noline }
+		paint { nochange }
+		outlinewidth { pathwidth }
+		outline {
+		  @BackEnd @Case {
+		    PostScript @Yield {
+		    "ldiagsolidcurvedarrowhead"
+		    # 0 0
+		    # [0 0 xsize ysize * 0.5 "ldiaglinebetween"
+		    #  xsize 0 xsize ysize "ldiaglineintersect" clockwise]
+		    # xsize ysize * 0.5
+		    # [xsize ysize * 0.5 0 ysize "ldiaglinebetween"
+		    #  xsize 0 xsize ysize "ldiaglineintersect" clockwise]
+		    # 0 ysize
+		    }
+		    PDF @Yield {}
+		  }
+		}
+	    {
+		length @Wide width @High
+	    }
+	}
+
+	def @OpenCurvedArrowHead
+	    named width { arrowwidth }
+	    named length { arrowlength }
+	    named pathwidth { pathwidth }
+	{
+	    @InsulatedNode
+		outlinestyle { noline }
+		paint { nochange }
+		outlinewidth { pathwidth }
+		outline {
+		  @BackEnd @Case {
+		    PostScript @Yield {
+		    pathwidth "ldiagopencurvedarrowhead"
+		    # LR:= { 0 0 xsize ysize * 0.5 "ldiaglinebetween"
+		    #    xsize 0 xsize ysize "ldiaglineintersect" }
+		    # UR:= { xsize ysize * 0.5 0 ysize "ldiaglinebetween"
+		    #      xsize 0 xsize ysize "ldiaglineintersect" }
+		    # PW2  := pathwidth * 0.5
+		    # UMID := {
+		    # 0 ysize * 0.5 + PW2  xsize ysize * 0.5 + PW2
+		    # {0 ysize} ++ 1f atangle { UR angleto {0 ysize} + 90d }
+		    # { 0 ysize } ldiaglineintersect
+		    # }
+		    # LMID := UMID -- { 0 pathwidth }
+		    # 0 0
+		    # [LR clockwise]
+		    # xsize ysize * 0.5
+		    # [UR clockwise]
+		    # 0 ysize
+		    # UMID
+		    # 0 ysize * 0.5 + PW2
+		    # 0 ysize * 0.5 - PW2
+		    # LMID
+		    # 0 0
+		    }
+		    PDF @Yield {}
+		  }
+		}
+	    {
+		length @Wide width @High
+	    }
+	}
+
+	def @HalfOpenCurvedArrowHead
+	    named width { arrowwidth }
+	    named length { arrowlength }
+	    named pathwidth { pathwidth }
+	{
+	    @InsulatedNode
+		outlinestyle { noline }
+		paint { nochange }
+		outlinewidth { pathwidth }
+		outline {
+		  @BackEnd @Case {
+		    PostScript @Yield {
+		    pathwidth "ldiaghalfopencurvedarrowhead"
+		    # LR:= { 0 0 xsize ysize * 0.5 "ldiaglinebetween"
+		    #      xsize 0 xsize ysize "ldiaglineintersect" }
+		    # UR:= { xsize ysize * 0.5 0 ysize "ldiaglinebetween"
+		    #      xsize 0 xsize ysize "ldiaglineintersect" }
+		    # BR:= { 0 0 LR 0 ysize UR "ldiaglineintersect" }
+		    # BRAD := { 0 0 } distance BR
+		    # PW2  := pathwidth * 0.5
+		    # XDIST := sqrt { BRAD*BRAD - PW2*PW2 }
+		    # UMID := BR ++ { XDIST PW2 }
+		    # LMID := BR ++ { XDIST 0 - PW2 }
+		    # 0 0
+		    # [LR clockwise]
+		    # xsize ysize * 0.5
+		    # [UR clockwise]
+		    # 0 ysize
+		    # [BR clockwise ]
+		    # UMID
+		    # 0 ysize * 0.5 + PW2
+		    # 0 ysize * 0.5 - PW2
+		    # LMID
+		    # [BR clockwise ]
+		    # 0 0
+		    }
+		    PDF @Yield {}
+		  }
+		}
+	    {
+		length @Wide width @High
+	    }
+	}
+
+	def @CircleArrowHead
+	    named width { arrowwidth }
+	    named length { arrowlength }
+	    named pathwidth { pathwidth }
+	{
+	    @InsulatedNode
+		outlinestyle { noline }
+		paint { nochange }
+		outlinewidth { pathwidth }
+		outline { circle }
+	    { length @Wide length @High }
+	}
+
+	def @BoxArrowHead
+	    named width { arrowwidth }
+	    named length { arrowlength }
+	    named pathwidth { pathwidth }
+	{
+	    @InsulatedNode
+		outlinestyle { noline }
+		paint { nochange }
+		outlinewidth { pathwidth }
+		outline { box }
+	    { length @Wide width @High }
+	}
+
+	def @ArrowHead
+	    named style { arrowstyle }
+	    named width { arrowwidth }
+	    named length { arrowlength }
+	    named pathwidth { pathwidth }
+	{
+	    style @Case {
+		solid          @Yield @SolidArrowHead
+				  width { width } length { length }
+				  pathwidth { pathwidth }
+		halfopen       @Yield @HalfOpenArrowHead
+				  width { width } length { length }
+				  pathwidth { pathwidth }
+		open           @Yield @OpenArrowHead
+				  width { width } length { length }
+				  pathwidth { pathwidth }
+		curvedsolid    @Yield @SolidCurvedArrowHead
+				  width { width } length { length }
+				  pathwidth { pathwidth }
+		curvedhalfopen @Yield @HalfOpenCurvedArrowHead
+				  width { width } length { length }
+				  pathwidth { pathwidth }
+		curvedopen     @Yield @OpenCurvedArrowHead
+				  width { width } length { length }
+				  pathwidth { pathwidth }
+		circle         @Yield @CircleArrowHead
+				  width { width } length { length }
+				  pathwidth { pathwidth }
+		box            @Yield @BoxArrowHead
+				  width { width } length { length }
+				  pathwidth { pathwidth }
+	    }
+	}
+
+        def @Link
+            import @Geometry named path
+                named from {}
+                named to {}
+                named bias {}
+                named fbias {}
+                named tbias {}
+                named radius {}
+                named xindent {}
+                named zindent {}
+                named frompt {}
+                named topt {}
+                named arrow {}
+                named arrowlength {}
+            					{ path
+						    from { from }
+						    to { to }
+						    bias { bias }
+						    fbias { fbias }
+						    tbias { tbias }
+						    radius { radius }
+						    xindent { xindent }
+						    zindent { zindent }
+						    frompt { frompt }
+						    topt { topt }
+						    arrow { arrow }
+						    arrowlength { arrowlength }
+						}
+            import @Geometry named from		{ from			}
+            import @Geometry named to		{ to			}
+            import @Geometry named bias		{ bias			}
+            import @Geometry named fbias	{ fbias			}
+            import @Geometry named tbias	{ tbias			}
+            import @Geometry named radius	{ radius		}
+            import @Geometry named xindent	{ xindent		}
+            import @Geometry named zindent	{ zindent		}
+            import @Geometry named frompt	{ frompt		}
+            import @Geometry named topt		{ topt		}
+            named pathstyle
+		named solid   { "/ldiagsolid"   }
+		named dashed  { "/ldiagdashed"  }
+		named cdashed { "/ldiagcdashed" }
+		named dotted  { "/ldiagdotted"  }
+		named noline  { "/ldiagnoline"  }
+						{ pathstyle		}
+            import @Geometry named pathdashlength { pathdashlength	}
+            import @Geometry named pathwidth
+		named thin   { 0.04 ft }
+		named medium { 0.08 ft }
+		named thick  { 0.12 ft }
+						{ pathwidth		}
+            import @Geometry named pathgap
+		named thin   { 0.08 ft }
+		named medium { 0.16 ft }
+		named thick  { 0.24 ft }
+						{ pathgap		}
+
+            named arrow				{ arrow			}
+            named arrowstyle			{ arrowstyle		}
+            named arrowwidth			{ arrowwidth		}
+            named arrowlength			{ arrowlength		}
+
+	    named linklabel			{ linklabel		}
+	    named linklabelmargin		{ linklabelmargin	}
+	    named linklabelfont			{ linklabelfont		}
+	    named linklabelbreak		{ linklabelbreak	}
+	    named linklabelformat right @Body	{ linklabelformat @Body	}
+	    import @Geometry named linklabelpos	{ linklabelpos		}
+	    named linklabelprox			{ linklabelprox		}
+	    import @Geometry named linklabelangle  { linklabelangle	}
+	    named linklabelctr			{ linklabelctr		}
+	    import @Geometry named linklabeladjust { linklabeladjust	}
+
+            named xlabel			{ xlabel		}
+            named xlabelmargin	        	{ xlabelmargin		}
+            named xlabelfont			{ xlabelfont		}
+            named xlabelbreak			{ xlabelbreak		}
+	    named xlabelformat right @Body	{ xlabelformat @Body	}
+            import @Geometry named xlabelpos	{ xlabelpos		}
+            named xlabelprox			{ xlabelprox		}
+            import @Geometry named xlabelangle	{ xlabelangle		}
+	    named xlabelctr			{ xlabelctr		}
+            import @Geometry named xlabeladjust	{ xlabeladjust		}
+
+            named ylabel			{ ylabel		}
+            named ylabelmargin			{ ylabelmargin		}
+            named ylabelfont			{ ylabelfont		}
+            named ylabelbreak			{ ylabelbreak		}
+	    named ylabelformat right @Body	{ ylabelformat @Body	}
+            import @Geometry named ylabelpos	{ ylabelpos		}
+            named ylabelprox			{ ylabelprox		}
+            import @Geometry named ylabelangle	{ ylabelangle		}
+	    named ylabelctr			{ ylabelctr		}
+            import @Geometry named ylabeladjust	{ ylabeladjust		}
+
+            named zlabel			{ zlabel		}
+            named zlabelmargin			{ zlabelmargin		}
+            named zlabelfont			{ zlabelfont		}
+            named zlabelbreak			{ zlabelbreak		}
+	    named zlabelformat right @Body	{ zlabelformat @Body	}
+            import @Geometry named zlabelpos	{ zlabelpos		}
+            named zlabelprox			{ zlabelprox		}
+            import @Geometry named zlabelangle	{ zlabelangle		}
+	    named zlabelctr			{ zlabelctr		}
+            import @Geometry named zlabeladjust	{ zlabeladjust		}
+
+            named fromlabel			{ fromlabel		}
+            named fromlabelmargin		{ fromlabelmargin	}
+            named fromlabelfont			{ fromlabelfont		}
+            named fromlabelbreak		{ fromlabelbreak	}
+	    named fromlabelformat right @Body	{ fromlabelformat @Body	}
+            import @Geometry named fromlabelpos	{ fromlabelpos		}
+            named fromlabelprox			{ fromlabelprox		}
+            import @Geometry named fromlabelangle  { fromlabelangle	}
+	    named fromlabelctr			{ fromlabelctr		}
+            import @Geometry named fromlabeladjust { fromlabeladjust	}
+
+            named tolabel			{ tolabel		}
+            named tolabelmargin			{ tolabelmargin		}
+            named tolabelfont			{ tolabelfont		}
+            named tolabelbreak			{ tolabelbreak		}
+	    named tolabelformat right @Body	{ tolabelformat @Body	}
+            import @Geometry named tolabelpos	{ tolabelpos		}
+            named tolabelprox			{ tolabelprox		}
+            import @Geometry named tolabelangle	{ tolabelangle		}
+	    named tolabelctr			{ tolabelctr		}
+            import @Geometry named tolabeladjust{ tolabeladjust		}
+
+        {
+	    def @XLabel
+	    {
+		@DoLabel
+		    which	{ "x"						}
+		    label	{ xlabel	     @Else linklabel		}
+		    labelmargin	{ xlabelmargin	     @Else linklabelmargin	}
+		    labelfont	{ xlabelfont	     @Else linklabelfont	}
+		    labelbreak	{ xlabelbreak	     @Else linklabelbreak	}
+		    labelformat { xlabelformat @Body @Else linklabelformat @Body}
+		    labelpos	{ xlabelpos	     @Else linklabelpos		}
+		    labelprox	{ xlabelprox	     @Else linklabelprox	}
+		    labelangle	{ xlabelangle	     @Else linklabelangle	}
+		    labelctr	{ xlabelctr	     @Else linklabelctr		}
+		    labeladjust	{ xlabeladjust	     @Else linklabeladjust	}
+	    }
+
+	    def @YLabel
+	    {
+		@DoLabel
+		    which	{ "y"						}
+		    label	{ ylabel	     @Else linklabel		}
+		    labelmargin	{ ylabelmargin	     @Else linklabelmargin	}
+		    labelfont	{ ylabelfont	     @Else linklabelfont	}
+		    labelbreak	{ ylabelbreak	     @Else linklabelbreak	}
+		    labelformat { ylabelformat @Body @Else linklabelformat @Body}
+		    labelpos	{ ylabelpos	     @Else linklabelpos		}
+		    labelprox	{ ylabelprox	     @Else linklabelprox	}
+		    labelangle	{ ylabelangle	     @Else linklabelangle	}
+		    labelctr	{ ylabelctr	     @Else linklabelctr		}
+		    labeladjust	{ ylabeladjust	     @Else linklabeladjust	}
+	    }
+
+	    def @ZLabel
+	    {
+		@DoLabel
+		    which	{ "z"						}
+		    label	{ zlabel	     @Else linklabel		}
+		    labelmargin	{ zlabelmargin	     @Else linklabelmargin	}
+		    labelfont	{ zlabelfont	     @Else linklabelfont	}
+		    labelbreak	{ zlabelbreak	     @Else linklabelbreak	}
+		    labelformat { zlabelformat @Body @Else linklabelformat @Body}
+		    labelpos	{ zlabelpos	     @Else linklabelpos		}
+		    labelprox	{ zlabelprox	     @Else linklabelprox	}
+		    labelangle	{ zlabelangle	     @Else linklabelangle	}
+		    labelctr	{ zlabelctr	     @Else linklabelctr		}
+		    labeladjust	{ zlabeladjust	     @Else linklabeladjust	}
+	    }
+
+	    def @FromArrow
+	    {
+		arrow @Case {
+		    { back both } @Yield {
+			@ArrowHead
+			    style { arrowstyle }
+			    width { arrowwidth }
+			    length { arrowlength }
+			    pathwidth { pathwidth }
+		    }
+		    else @Yield ""
+		}
+	    }
+
+	    def @ToArrow
+	    {
+		arrow @Case {
+		    { yes forward both } @Yield {
+			@ArrowHead
+			    style { arrowstyle }
+			    width { arrowwidth }
+			    length { arrowlength }
+			    pathwidth { pathwidth }
+		    }
+		    else @Yield ""
+		}
+	    }
+
+	    import @Geometry
+	    def @LinePath
+	    {
+		@BackEnd @Case {
+		  PostScript @Yield {
+	       {arrow @FromArrowLength arrowlength}
+	       {arrow @ToArrowLength arrowlength}
+	       "{" from "}" "{" to "}"
+	       xindent zindent "ldiaglinepath"
+               # FROM	:< {from??CTR angleto to??CTR}
+               # FROM	:: from boundaryatangle FROM@ANGLE
+               # 	++ {arrow @FromArrowLength arrowlength}atangle FROM@ANGLE
+               # TO  	:< FROM@ANGLE
+               # TO  	:: to boundaryatangle { TO@ANGLE - 180d }
+               # ++ {arrow @ToArrowLength arrowlength} atangle {TO@ANGLE - 180d}
+               # 		
+               # LMID	:: FROM ** 0.5 ++ TO ** 0.5
+               # LMID	:< FROM@ANGLE
+               # XINDENT	:= xindent min { FROM distance LMID }
+               # LFROM	:: FROM ++ XINDENT atangle FROM@ANGLE
+               # LFROM	:< FROM@ANGLE
+               # ZINDENT	:= zindent min { TO distance LMID }
+               # LTO 	:: TO -- ZINDENT atangle FROM@ANGLE
+               # LTO 	:< FROM@ANGLE
+	       #
+               # if cond { direct }
+               # then { FROM TO }
+               # else { FROM LFROM LMID LTO TO }
+		  }
+		  PDF @Yield {}
+		}
+	    }
+
+	    import @Geometry
+	    def @DoubleLinePath
+	    {
+		@BackEnd @Case {
+		  PostScript @Yield {
+	       {arrow @FromArrowLength arrowlength}
+	       {arrow @ToArrowLength arrowlength}
+	       "{" from "}" "{" to "}"
+	       xindent zindent pathgap "ldiagdoublelinepath"
+               # FROM	:< {from??CTR angleto to??CTR}
+               # FROM	:: from boundaryatangle FROM@ANGLE
+               # 	++ {arrow @FromArrowLength arrowlength}atangle FROM@ANGLE
+               # TO  	:< FROM@ANGLE
+               # TO  	:: to boundaryatangle { TO@ANGLE - 180d }
+               # ++ {arrow @ToArrowLength arrowlength} atangle {TO@ANGLE - 180d}
+               # 		
+               # LMID	:: FROM ** 0.5 ++ TO ** 0.5
+               # LMID	:< FROM@ANGLE
+               # XINDENT	:= xindent min { FROM distance LMID }
+               # LFROM	:: FROM ++ XINDENT atangle FROM@ANGLE
+               # LFROM	:< FROM@ANGLE
+               # ZINDENT	:= zindent min { TO distance LMID }
+               # LTO 	:: TO -- ZINDENT atangle FROM@ANGLE
+               # LTO 	:< FROM@ANGLE
+	       #
+               # if cond { direct }
+               # then { FROM TO }
+               # else { FROM LFROM LMID LTO TO }
+		  }
+		  PDF @Yield {}
+		}
+	    }
+
+	    import @Geometry
+	    def @ACurvePath
+	    {
+		@BackEnd @Case {
+		  PostScript @Yield {
+	       {arrow @FromArrowLength arrowlength}
+	       {arrow @ToArrowLength arrowlength}
+	       "{" from "}" "{" to "}"
+	       xindent zindent bias "ldiagacurvepath"
+               #  #B1	:= bias max 0.02f
+               #  #B2	:= { from??CTR distance to??CTR } * 0.5
+               #  #BIAS    := B1 min B2
+	       #  BIAS  := bias max 0.02f
+               #  XMID	:= from??CTR ** 0.5 ++ to??CTR ** 0.5
+               #  XTOP	:= XMID ++ BIAS atangle {from??CTR angleto to??CTR - 90d}
+               #  CTR  	:= { from??CTR XTOP ldiaglinebetween
+               #  	     to??CTR   XTOP ldiaglinebetween ldiaglineintersect }
+               #  FROM	:: aabout
+               #  		circum { from }
+               #  		extra  { arrow @FromArrowLength arrowlength }
+               #  		centre { CTR }
+	       #  FROM 	:< if cond { from??CTR distance FROM > 0 }
+               #  	      then { from??CTR angleto FROM }
+	       #  	      else { CTR angleto FROM + 90d }
+               #  TO	:: cabout
+               #  		circum { to }
+               #  		extra  { arrow @ToArrowLength arrowlength }
+               #  		centre { CTR }
+               #  TO   	:< if cond { TO distance to??CTR > 0 }
+               #  	      then { TO angleto to??CTR }
+               #  	      else { CTR angleto TO + 90d }
+               # 
+               #  RADIUS	:= CTR distance FROM
+               #  LMID 	:: CTR ++ RADIUS atangle {
+               #   CTR angleto FROM +
+	       #   { {360d + {CTR angleto TO} - {CTR angleto FROM}} mod 360 } / 2
+	       #   }
+               #  LMID 	:< CTR angleto LMID  + 90d
+               #
+               #  XINDENT	:= xindent min { FROM distance LMID }
+               #  LFROM	:: CTR ++ RADIUS atangle {
+               #  	   CTR angleto { FROM ++ XINDENT atangle FROM@ANGLE } }
+               #  LFROM	:< CTR angleto LFROM + 90d
+               #  ZINDENT	:= zindent min { TO distance LMID }
+               #  LTO  	:: CTR ++ RADIUS atangle {
+               #  	   CTR angleto { TO ++ ZINDENT atangle {TO@ANGLE+180d}}}
+               #  LTO  	:< CTR angleto LTO   + 90d
+               #
+               #  if cond { direct }
+	       #  then { FROM [CTR] TO }
+               #  else { FROM [CTR] LFROM [CTR] LMID [CTR] LTO [CTR] TO }
+		  }
+		  PDF @Yield {}
+		}
+	    }
+
+	    import @Geometry
+	    def @CCurvePath
+	    {
+		@BackEnd @Case {
+		  PostScript @Yield {
+	       {arrow @FromArrowLength arrowlength}
+	       {arrow @ToArrowLength arrowlength}
+	       "{" from "}" "{" to "}"
+	       xindent zindent bias "ldiagccurvepath"
+              #  #B1     := bias max 0.02f
+              #  #B2     := { from??CTR distance to??CTR } * 0.5
+              #  #BIAS   := B1 min B2
+              #  BIAS   := bias max 0.02f
+              #  XMID   := from??CTR ** 0.5 ++ to??CTR ** 0.5
+              #  XTOP   := XMID ++ BIAS atangle {from??CTR angleto to??CTR + 90d}
+              #  CTR    := { from??CTR XTOP ldiaglinebetween
+              #              to??CTR   XTOP ldiaglinebetween ldiaglineintersect }
+              #  FROM   :: cabout
+              #                  circum { from }
+              #                  extra  { arrow @FromArrowLength arrowlength }
+              #                  centre { CTR }
+              #  FROM   :< if cond { from??CTR distance FROM > 0 }
+              #               then { from??CTR angleto FROM }
+              #               else { CTR angleto FROM - 90d }
+              #  TO     :: aabout
+              #                 circum { to }
+              #                 extra  { arrow @ToArrowLength arrowlength }
+              #                 centre { CTR }
+              #  TO     :< if cond { TO distance to??CTR > 0 }
+              #               then { TO angleto to??CTR }
+              #               else { CTR angleto TO - 90d }
+              #
+              #  RADIUS  := CTR distance FROM
+              #  LMID    :: CTR ++ RADIUS atangle {
+              #   CTR angleto TO +
+              #   { {360d + {CTR angleto FROM} - {CTR angleto TO} } mod 360 } / 2
+              #   }
+              #  LMID    :< CTR angleto LMID  - 90d
+              #
+              #  XINDENT := xindent min { FROM distance LMID }
+              #  LFROM   :: CTR ++ RADIUS atangle {
+              #             CTR angleto { FROM ++ XINDENT atangle FROM@ANGLE } }
+              #  LFROM   :< CTR angleto LFROM - 90d
+              #  ZINDENT := zindent min { TO distance LMID }
+              #  LTO     :: CTR ++ RADIUS atangle {
+              #             CTR angleto { TO ++ ZINDENT atangle {TO@ANGLE+180d}}}
+              #  LTO     :< CTR angleto LTO   - 90d
+              #
+              #  if cond { direct }
+              #  then { FROM [CTR clockwise] TO }
+              #  else { FROM [CTR clockwise] LFROM [CTR clockwise]
+              #         LMID [CTR clockwise] LTO   [CTR clockwise] TO }
+		  }
+		  PDF @Yield {}
+		}
+          }
+
+	    import @Geometry
+	    def @BezierPath
+	    {
+		@BackEnd @Case {
+		  PostScript @Yield {
+	       {arrow @FromArrowLength arrowlength}
+	       {arrow @ToArrowLength arrowlength}
+	       "{" from "}" "{" to "}"
+	       xindent zindent [ frompt ] [ topt ] "ldiagbezierpath"
+              # FROM      :< from??CTR angleto frompt
+              # FROM      :: from boundaryatangle FROM@ANGLE
+              # ++ {arrow @FromArrowLength arrowlength} atangle FROM@ANGLE
+              # TO        :< topt angleto to??CTR
+              # TO        :: to boundaryatangle { TO@ANGLE + 180d }
+              # ++ {arrow @ToArrowLength arrowlength} atangle { TO@ANGLE + 180d }
+              # LFROM     :: FROM ++ { xindent atangle FROM@ANGLE }
+              # LFROM     :< FROM@ANGLE
+              # LTO       :: TO ++ zindent atangle { TO@ANGLE + 180d }
+              # LTO       :< TO@ANGLE
+              # LMID       :: { FROM ++ TO ++ frompt ++ topt } ** 0.25
+              # FROM [frompt topt] TO
+		  }
+		  PDF @Yield {}
+		}
+	    }
+
+	    import @Geometry
+	    def @VHLinePath
+	    {
+		@BackEnd @Case {
+		  PostScript @Yield {
+	      {arrow @FromArrowLength arrowlength}
+	      {arrow @ToArrowLength arrowlength}
+	      "{" from "}" "{" to "}"
+	      xindent zindent "ldiagvhlinepath"
+              # CTR     := { {xcoord from??CTR} {ycoord to??CTR} }
+              # FANG    := from??CTR angleto CTR
+              # TANG    := to??CTR angleto CTR
+              # FROM    :: from boundaryatangle FANG
+              # ++ {arrow @FromArrowLength arrowlength} atangle FANG
+              # FROM    :< FANG
+              # TO      :: to boundaryatangle TANG
+              # ++ {arrow @ToArrowLength arrowlength} atangle TANG
+              # TO      :< TANG + 180d
+              # FDIST   := FROM distance CTR
+              # TDIST   := TO distance CTR
+              # XINDENT := xindent min FDIST
+              # ZINDENT := zindent min TDIST
+              # LFROM   :: FROM ++ XINDENT atangle FANG
+              # LFROM   :< FROM@ANGLE
+              # LTO     :: TO ++ ZINDENT atangle TANG
+              # LTO     :< TO@ANGLE
+              # LMID    :: CTR 
+              # LMID    :< {1f atangle {FANG + 180d}} angleto
+              #            {1f atangle {TANG + 180d}}
+              # FROM LFROM LMID LTO TO
+		  }
+		  PDF @Yield {}
+		}
+	    }
+
+	    import @Geometry
+	    def @VHCurvePath
+	    {
+		@BackEnd @Case {
+		  PostScript @Yield {
+	      {arrow @FromArrowLength arrowlength}
+	      {arrow @ToArrowLength arrowlength}
+	      "{" from "}" "{" to "}"
+	      xindent zindent radius "ldiagvhcurvepath"
+              # CTR     := { {xcoord from??CTR} {ycoord to??CTR} }
+              # FANG    := from??CTR angleto CTR
+              # TANG    := to??CTR angleto CTR
+              # FROM    :: from boundaryatangle FANG
+              # ++ {arrow @FromArrowLength arrowlength} atangle FANG
+              # FROM    :< FANG
+              # TO      :: to boundaryatangle TANG
+              # ++ {arrow @ToArrowLength arrowlength} atangle TANG
+              # TO      :< TANG + 180d
+              # FDIST   := FROM distance CTR
+              # TDIST   := TO distance CTR
+              # RADIUS  := radius min FDIST min TDIST 
+              # XINDENT := xindent min { FDIST - RADIUS }
+              # ZINDENT := zindent min { TDIST - RADIUS }
+              # LFROM   :: FROM ++ XINDENT atangle FANG
+              # LFROM   :< FROM@ANGLE
+              # LTO     :: TO ++ ZINDENT atangle TANG
+              # LTO     :< TO@ANGLE
+              # FCTR    := CTR ++ RADIUS atangle { FROM@ANGLE + 180d }
+              # TCTR    := CTR ++ RADIUS atangle { TO@ANGLE          }
+              # XCTR    := CTR ++ RADIUS atangle { FROM@ANGLE + 180d }
+              #                ++ RADIUS atangle { TO@ANGLE }
+              # LMID    :: XCTR ++ RADIUS atangle { XCTR angleto CTR }
+              # LMID    :< FCTR angleto TCTR
+              # FROM LFROM FCTR
+              #     { FCTR angleto TCTR } quadcase
+              #       0        {   }
+              #       0-90     { [XCTR clockwise] }
+              #       90       {   }
+              #       90-180   { [XCTR] }
+              #       180      {   }
+              #       180-270  { [XCTR clockwise] }
+              #       270      {   }
+              #       270-360  { [XCTR] }
+              # TCTR LTO TO
+		  }
+		  PDF @Yield {}
+		}
+	    }
+
+	    import @Geometry
+	    def @HVLinePath
+	    {
+		@BackEnd @Case {
+		  PostScript @Yield {
+	      {arrow @FromArrowLength arrowlength}
+	      {arrow @ToArrowLength arrowlength}
+	      "{" from "}" "{" to "}"
+	      xindent zindent "ldiaghvlinepath"
+              # CTR     := { {xcoord to??CTR} {ycoord from??CTR} }
+              # FANG    := from??CTR angleto CTR
+              # TANG    := to??CTR angleto CTR
+              # FROM    :: from boundaryatangle FANG
+              # ++ {arrow @FromArrowLength arrowlength} atangle FANG
+              # FROM    :< FANG
+              # TO      :: to boundaryatangle TANG
+              # ++ {arrow @ToArrowLength arrowlength} atangle TANG
+              # TO      :< TANG + 180d
+              # FDIST   := FROM distance CTR
+              # TDIST   := TO distance CTR
+              # XINDENT := xindent min FDIST
+              # ZINDENT := zindent min TDIST
+              # LFROM   :: FROM ++ XINDENT atangle FANG
+              # LFROM   :< FROM@ANGLE
+              # LTO     :: TO ++ ZINDENT atangle TANG
+              # LTO     :< TO@ANGLE
+              # LMID    :: CTR 
+              # LMID    :< {1f atangle {FANG + 180d}} angleto
+              #            {1f atangle {TANG + 180d}}
+              # FROM LFROM LMID LTO TO
+		  }
+		  PDF @Yield {}
+		}
+	    }
+
+	    import @Geometry
+	    def @HVCurvePath
+	    {
+		@BackEnd @Case {
+		  PostScript @Yield {
+	      {arrow @FromArrowLength arrowlength}
+	      {arrow @ToArrowLength arrowlength}
+	      "{" from "}" "{" to "}"
+	      xindent zindent radius "ldiaghvcurvepath"
+              # CTR     := { {xcoord to??CTR} {ycoord from??CTR} }
+              # FANG    := from??CTR angleto CTR
+              # TANG    := to??CTR angleto CTR
+              # FROM    :: from boundaryatangle FANG
+              # ++ {arrow @FromArrowLength arrowlength} atangle FANG
+              # FROM    :< FANG
+              # TO      :: to boundaryatangle TANG
+              # ++ {arrow @ToArrowLength arrowlength} atangle TANG
+              # TO      :< TANG + 180d
+              # FDIST   := FROM distance CTR
+              # TDIST   := TO distance CTR
+              # RADIUS  := radius min FDIST min TDIST 
+              # XINDENT := xindent min { FDIST - RADIUS }
+              # ZINDENT := zindent min { TDIST - RADIUS }
+              # LFROM   :: FROM ++ XINDENT atangle FANG
+              # LFROM   :< FROM@ANGLE
+              # LTO     :: TO ++ ZINDENT atangle TANG
+              # LTO     :< TO@ANGLE
+              # FCTR    := CTR ++ RADIUS atangle { FROM@ANGLE + 180d }
+              # TCTR    := CTR ++ RADIUS atangle { TO@ANGLE          }
+              # XCTR    := CTR ++ RADIUS atangle { FROM@ANGLE + 180d }
+              #                ++ RADIUS atangle { TO@ANGLE }
+              # LMID    :: XCTR ++ RADIUS atangle { XCTR angleto CTR }
+              # LMID    :< FCTR angleto TCTR
+              # FROM LFROM FCTR
+              #     { FCTR angleto TCTR } quadcase
+              #       0        {   }
+              #       0-90     { [XCTR] }
+              #       90       {   }
+              #       90-180   { [XCTR clockwise] }
+              #       180      {   }
+              #       180-270  { [XCTR] }
+              #       270      {   }
+              #       270-360  { [XCTR clockwise] }
+              # TCTR LTO TO
+		  }
+		  PDF @Yield {}
+		}
+	    }
+
+	    import @Geometry
+	    def @LVRLinePath
+	    {
+		@BackEnd @Case {
+		  PostScript @Yield {
+	      {arrow @FromArrowLength arrowlength}
+	      {arrow @ToArrowLength arrowlength}
+	      "{" from "}" "{" to "}"
+	      xindent zindent bias "ldiaglvrlinepath"
+              # FROM    :: from boundaryatangle 180d
+              # ++ {arrow @FromArrowLength arrowlength} atangle 180d
+              # FROM    :< 180d
+              # TO      :: to boundaryatangle 180d
+              # ++ {arrow @ToArrowLength arrowlength} atangle 180d
+              # TO      :< 0d
+              # XLEFT   := {{xcoord FROM} min {xcoord TO}} - bias
+              # P1      :: { XLEFT ycoord FROM }
+              # P2      :: { XLEFT ycoord TO   }
+              # VERT    := P1 angleto P2
+              # P1      :< P1 angleto {P1++{1f atangle 180d}++{1f atangle VERT}}
+              # P2      :< P2 angleto {P2++{1f atangle 0d}  ++{1f atangle VERT}}
+              # LMID    :: P1 ** 0.5 ++ P2 ** 0.5
+              # LMID    :< VERT
+              # XINDENT := xindent min {FROM distance P1}
+              # ZINDENT := zindent min {P2   distance TO}
+              # LFROM   :: FROM -- { XINDENT 0 }
+              # LFROM   :< 180d
+              # LTO     :: TO -- { ZINDENT 0 }
+              # LTO     :< 0d
+              # FROM LFROM P1 LMID P2 LTO TO
+		  }
+		  PDF @Yield {}
+		}
+	    }
+
+	    import @Geometry
+	    def @LVRCurvePath
+	    {
+		@BackEnd @Case {
+		  PostScript @Yield {
+	      {arrow @FromArrowLength arrowlength}
+	      {arrow @ToArrowLength arrowlength}
+	      "{" from "}" "{" to "}"
+	      xindent zindent bias radius "ldiaglvrcurvepath"
+              # FROM    :: from boundaryatangle 180d
+              # ++ {arrow @FromArrowLength arrowlength} atangle 180d
+              # FROM    :< 180d
+              # TO      :: to boundaryatangle 180d
+              # ++ {arrow @ToArrowLength arrowlength} atangle 180d
+              # TO      :< 0d
+              # XLEFT   := {{xcoord FROM} min {xcoord TO}} - bias
+              # XP1     := { XLEFT ycoord FROM }
+              # XP2     := { XLEFT ycoord TO   }
+              # VERT    := XP1 angleto XP2
+              # LMID    :: XP1 ** 0.5 ++ XP2 ** 0.5
+              # LMID    :< VERT
+              # XINDENT := xindent min {FROM distance XP1}
+              # ZINDENT := zindent min {XP2   distance TO}
+              # LFROM   :: FROM -- { XINDENT 0 }
+              # LFROM   :< 180d
+              # LTO     :: TO -- { ZINDENT 0 }
+              # LTO     :< 0d
+              # RADIUS  := radius min { { XP1 distance XP2 } / 2 }
+              # XP1PRE  := XP1 ++ { RADIUS atangle 0d }
+              # XP1POST := XP1 ++ { RADIUS atangle VERT }
+              # XP1CTR  := XP1PRE ++ { RADIUS atangle VERT }
+              # P1      :: XP1CTR ++ { RADIUS atangle { XP1CTR angleto XP1 } }
+              # P1      :< XP1PRE angleto XP1POST
+              # XP2PRE  := XP2 -- { RADIUS atangle VERT }
+              # XP2POST := XP2 ++ { RADIUS atangle 0d }
+              # XP2CTR  := XP2PRE ++ { RADIUS atangle 0d }
+              # P2      :: XP2CTR ++ { RADIUS atangle { XP2CTR angleto XP2 } }
+              # P2      :< XP2PRE angleto XP2POST
+              # FROM LFROM XP1PRE
+              #   {round VERT} quadcase
+              #     90 { [XP1CTR clockwise] P1 [XP1CTR clockwise] }
+              #     270 { [XP1CTR] P1 [XP1CTR] }
+              # XP1POST LMID XP2PRE
+              #   {round VERT} quadcase
+              #     90 { [XP2CTR clockwise] P2 [XP2CTR clockwise] }
+              #     270 { [XP2CTR] P2 [XP2CTR] }
+              # XP2POST LTO TO
+		  }
+		  PDF @Yield {}
+		}
+	    }
+
+	    import @Geometry
+	    def @RVLLinePath
+	    {
+		@BackEnd @Case {
+		  PostScript @Yield {
+	      {arrow @FromArrowLength arrowlength}
+	      {arrow @ToArrowLength arrowlength}
+	      "{" from "}" "{" to "}"
+	      xindent zindent bias "ldiagrvllinepath"
+              # FROM    :: from boundaryatangle 0d
+              # ++ {arrow @FromArrowLength arrowlength} atangle 0d
+              # FROM    :< 0d
+              # TO      :: to boundaryatangle 0d
+              # ++ {arrow @ToArrowLength arrowlength} atangle 0d
+              # TO      :< 180d
+              # XRIGHT  := {{xcoord FROM} max {xcoord TO}} + bias
+              # P1      :: { XRIGHT ycoord FROM }
+              # P2      :: { XRIGHT ycoord TO   }
+              # VERT    := P1 angleto P2
+              # P1      :< P1 angleto {P1++{1f atangle 0d}  ++{1f atangle VERT}}
+              # P2      :< P2 angleto {P2++{1f atangle 180d}++{1f atangle VERT}}
+              # LMID    :: P1 ** 0.5 ++ P2 ** 0.5
+              # LMID    :< VERT
+              # XINDENT := xindent min {FROM distance P1}
+              # ZINDENT := zindent min {P2   distance TO}
+              # LFROM   :: FROM ++ { XINDENT 0 }
+              # LFROM   :< 0d
+              # LTO     :: TO ++ { ZINDENT 0 }
+              # LTO     :< 180d
+              # FROM LFROM P1 LMID P2 LTO TO
+		  }
+		  PDF @Yield {}
+		}
+	    }
+
+	    import @Geometry
+	    def @RVLCurvePath
+	    {
+		@BackEnd @Case {
+		  PostScript @Yield {
+	      {arrow @FromArrowLength arrowlength}
+	      {arrow @ToArrowLength arrowlength}
+	      "{" from "}" "{" to "}"
+	      xindent zindent bias radius "ldiagrvlcurvepath"
+              # FROM    :: from boundaryatangle 0d
+              # ++ {arrow @FromArrowLength arrowlength} atangle 0d
+              # FROM    :< 0d
+              # TO      :: to boundaryatangle 0d
+              # ++ {arrow @ToArrowLength arrowlength} atangle 0d
+              # TO      :< 180d
+              # XRIGHT  := {{xcoord FROM} max {xcoord TO}} + bias
+              # XP1     := { XRIGHT ycoord FROM }
+              # XP2     := { XRIGHT ycoord TO   }
+              # VERT    := XP1 angleto XP2
+              # LMID    :: XP1 ** 0.5 ++ XP2 ** 0.5
+              # LMID    :< VERT
+              # XINDENT := xindent min {FROM distance XP1}
+              # ZINDENT := zindent min {XP2   distance TO}
+              # LFROM   :: FROM ++ { XINDENT 0 }
+              # LFROM   :< 0d
+              # LTO     :: TO ++ { ZINDENT 0 }
+              # LTO     :< 180d
+              # RADIUS  := radius min { { XP1 distance XP2 } * 0.5 }
+              # XP1PRE  := XP1 ++ { RADIUS atangle 180d }
+              # XP1POST := XP1 ++ { RADIUS atangle VERT }
+              # XP1CTR  := XP1PRE ++ { RADIUS atangle VERT }
+              # P1      :: XP1CTR ++ { RADIUS atangle { XP1CTR angleto XP1 } }
+              # P1      :< XP1PRE angleto XP1POST
+              # XP2PRE  := XP2 -- { RADIUS atangle VERT }
+              # XP2POST := XP2 ++ { RADIUS atangle 180d }
+              # XP2CTR  := XP2PRE ++ { RADIUS atangle 180d }
+              # P2      :: XP2CTR ++ { RADIUS atangle { XP2CTR angleto XP2 } }
+              # P2      :< XP2PRE angleto XP2POST
+              # FROM LFROM XP1PRE
+              #   {round VERT} quadcase
+              #     90 { [XP1CTR] P1 [XP1CTR] }
+              #     270 { [XP1CTR clockwise] P1 [XP1CTR clockwise] }
+              # XP1POST LMID XP2PRE
+              #   {round VERT} quadcase
+              #     90 { [XP2CTR] P2 [XP2CTR] }
+              #     270 { [XP2CTR clockwise] P2 [XP2CTR clockwise] }
+              # XP2POST LTO TO
+		  }
+		  PDF @Yield {}
+		}
+	    }
+
+	    import @Geometry
+	    def @DWrapLinePath
+	    {
+		@BackEnd @Case {
+		  PostScript @Yield {
+	      {arrow @FromArrowLength arrowlength}
+	      {arrow @ToArrowLength arrowlength}
+	      "{" from "}" "{" to "}"
+	      xindent zindent bias fbias tbias "ldiagdwraplinepath"
+              # DIRN	:= if cond { xcoord from??CTR < xcoord to??CTR }
+              # 	      then { 180d } else { 0d }
+              # FROM	:: from boundaryatangle DIRN
+              # ++ {arrow @FromArrowLength arrowlength} atangle DIRN
+              # FROM	:< DIRN
+              # TO	:: to boundaryatangle { DIRN + 180d }
+              # ++ {arrow @ToArrowLength arrowlength} atangle { DIRN + 180d }
+              # TO	:< DIRN
+              # P1	:: FROM ++ {fbias max 0} atangle DIRN
+              # P1	:< if cond { DIRN = 180d } then { 225d } else { -45d }
+              # P4	:: TO ++ {tbias max 0} atangle { DIRN + 180d }
+              # P4	:< if cond { DIRN = 180d } then { 135d } else { 45d }
+              # YC	:= ycoord { from boundaryatangle 270d } min
+              # 	   ycoord { to   boundaryatangle 270d }
+              # 	   - { bias max 0 }
+              # P2	:: { xcoord P1 YC }
+              # P2	:< P4@ANGLE - 180d
+              # P3	:: { xcoord P4 YC }
+              # P3	:< P1@ANGLE - 180d
+              # XINDENT	:= xindent min { FROM distance P1 }
+              # LFROM	:: FROM ++ XINDENT atangle DIRN
+              # LFROM	:< FROM@ANGLE
+              # ZINDENT	:= zindent min { TO distance P4 }
+              # LTO	:: TO ++ ZINDENT atangle { DIRN + 180d }
+              # LTO	:< TO@ANGLE
+              # LMID	:: P2 ** 0.5 ++ P3 ** 0.5
+              # LMID	:< DIRN - 180d
+              # FROM P1 P2 P3 P4 TO
+		  }
+		  PDF @Yield {}
+		}
+	    }
+
+	    import @Geometry
+	    def @DWrapCurvePath
+	    {
+		@BackEnd @Case {
+		  PostScript @Yield {
+	      {arrow @FromArrowLength arrowlength}
+	      {arrow @ToArrowLength arrowlength}
+	      "{" from "}" "{" to "}"
+	      xindent zindent bias fbias tbias radius "ldiagdwrapcurvepath"
+              # DIRN	:= if cond { xcoord from??CTR < xcoord to??CTR }
+              # 	      then { 180d } else { 0d }
+              # CLOCK	:= if cond { xcoord from??CTR < xcoord to??CTR }
+              # 	      then { anticlockwise } else { clockwise }
+              # FROM	:: from boundaryatangle DIRN
+              # ++ {arrow @FromArrowLength arrowlength} atangle DIRN
+              # FROM	:< DIRN
+              # TO	:: to boundaryatangle { DIRN + 180d }
+              # ++ {arrow @ToArrowLength arrowlength} atangle { DIRN + 180d }
+              # TO	:< DIRN
+              #
+              # XP1	:= FROM ++ {fbias max 0} atangle DIRN
+              # XP4	:= TO ++ {tbias max 0} atangle { DIRN + 180d }
+              # YC	:= ycoord { from boundaryatangle 270d } min
+              # 	   ycoord { to   boundaryatangle 270d }
+              # 	   - { bias max 0 }
+              # XP2	:= { xcoord XP1 YC }
+              # XP3	:= { xcoord XP4 YC }
+              #
+              # RP1	:= radius min { XP1 distance FROM } min
+              # 	   { { XP1 distance XP2 } / 2 }
+              # XP1PRE	:= XP1 ++ RP1 atangle { XP1 angleto FROM }
+              # XP1POST := XP1 ++ RP1 atangle { XP1 angleto XP2  }
+              # XP1CTR  := XP1PRE ++ RP1 atangle { XP1 angleto XP2  }
+              # P1	:: XP1CTR ++ RP1 atangle { XP1CTR angleto XP1 }
+              # P1	:< XP1CTR angleto P1 + DIRN - 90d
+              #
+              # RP2	:= radius min { { XP1 distance XP2 } / 2 }
+              # 	     min { { XP2 distance XP3 } / 2 }
+              # XP2PRE	:= XP2 ++ RP2 atangle { XP2 angleto XP1 }
+              # XP2POST	:= XP2 ++ RP2 atangle { XP2 angleto XP3 }
+              # XP2CTR	:= XP2PRE ++ RP2 atangle { XP2 angleto XP3 }
+              # P2	:: XP2CTR ++ RP2 atangle { XP2CTR angleto XP2 }
+              # P2	:< XP2CTR angleto P2 + DIRN - 90d
+              #
+              # RP3	:= radius min { { XP2 distance XP3 } / 2 }
+              # 	     min { { XP3 distance XP4 } / 2 }
+              # XP3PRE	:= XP3 ++ RP3 atangle { XP3 angleto XP2 }
+              # XP3POST	:= XP3 ++ RP3 atangle { XP3 angleto XP4 }
+              # XP3CTR	:= XP3PRE ++ RP3 atangle { XP3 angleto XP4 }
+              # P3	:: XP3CTR ++ RP3 atangle { XP3CTR angleto XP3 }
+              # P3	:< XP3CTR angleto P3 + DIRN - 90d
+              #
+              # RP4	:= radius min { { XP4 distance XP3 } / 2 }
+              # 	     min { XP4 distance TO }
+              # XP4PRE	:= XP4 ++ RP4 atangle { XP4 angleto XP3 }
+              # XP4POST := XP4 ++ RP4 atangle { XP4 angleto TO  }
+              # XP4CTR  := XP4PRE ++ RP4 atangle { XP4 angleto TO  }
+              # P4	:: XP4CTR ++ RP4 atangle { XP4CTR angleto XP4 }
+              # P4	:< XP4CTR angleto P4 + DIRN - 90d
+              #
+              # XINDENT	:= xindent min { FROM distance XP1PRE }
+              # LFROM	:: FROM ++ XINDENT atangle DIRN
+              # LFROM	:< FROM@ANGLE
+              #
+              # LMID	:: XP2 ** 0.5 ++ XP3 ** 0.5
+              # LMID	:< DIRN - 180d
+              #
+              # ZINDENT	:= zindent min { TO distance XP4POST }
+              # LTO	:: TO ++ ZINDENT atangle { DIRN + 180d }
+              # LTO	:< TO@ANGLE
+              #
+              # FROM LFROM
+              # XP1PRE [XP1CTR CLOCK] XP1POST
+              # XP2PRE [XP2CTR CLOCK] XP2POST
+              # LMID
+              # XP3PRE [XP3CTR CLOCK] XP3POST
+              # XP4PRE [XP4CTR CLOCK] XP4POST
+              # LTO TO
+		  }
+		  PDF @Yield {}
+		}
+	    }
+
+	    import @Geometry
+	    def @UWrapLinePath
+	    {
+		@BackEnd @Case {
+		  PostScript @Yield {
+	      {arrow @FromArrowLength arrowlength}
+	      {arrow @ToArrowLength arrowlength}
+	      "{" from "}" "{" to "}"
+	      xindent zindent bias fbias tbias "ldiaguwraplinepath"
+              # DIRN	:= if cond { xcoord from??CTR < xcoord to??CTR }
+              # 	      then { 180d } else { 0d }
+              # FROM	:: from boundaryatangle DIRN
+              # ++ {arrow @FromArrowLength arrowlength} atangle DIRN
+              # FROM	:< DIRN
+              # TO	:: to boundaryatangle { DIRN + 180d }
+              # ++ {arrow @ToArrowLength arrowlength} atangle { DIRN + 180d }
+              # TO	:< DIRN
+              # P1	:: FROM ++ {fbias max 0} atangle DIRN
+              # P1	:< if cond { DIRN = 180d } then { 135d } else { 45d }
+              # P4	:: TO ++ {tbias max 0} atangle { DIRN + 180d }
+              # P4	:< if cond { DIRN = 180d } then { 225d } else { -45d }
+              # YC	:= ycoord { from boundaryatangle 90d } max
+              # 	   ycoord { to   boundaryatangle 90d }
+              # 	   + { bias max 0 }
+              # P2	:: { xcoord P1 YC }
+              # P2	:< P4@ANGLE - 180d
+              # P3	:: { xcoord P4 YC }
+              # P3	:< P1@ANGLE - 180d
+              # XINDENT	:= xindent min { FROM distance P1 }
+              # LFROM	:: FROM ++ XINDENT atangle DIRN
+              # LFROM	:< FROM@ANGLE
+              # ZINDENT	:= zindent min { TO distance P4 }
+              # LTO	:: TO ++ ZINDENT atangle { DIRN + 180d }
+              # LTO	:< TO@ANGLE
+              # LMID	:: P2 ** 0.5 ++ P3 ** 0.5
+              # LMID	:< DIRN - 180d
+              # FROM P1 P2 P3 P4 TO
+		  }
+		  PDF @Yield {}
+		}
+	    }
+
+	    import @Geometry
+	    def @UWrapCurvePath
+	    {
+		@BackEnd @Case {
+		  PostScript @Yield {
+	      {arrow @FromArrowLength arrowlength}
+	      {arrow @ToArrowLength arrowlength}
+	      "{" from "}" "{" to "}"
+	      xindent zindent bias fbias tbias radius "ldiaguwrapcurvepath"
+              # DIRN	:= if cond { xcoord from??CTR < xcoord to??CTR }
+              # 	      then { 180d } else { 0d }
+              # CLOCK	:= if cond { xcoord from??CTR < xcoord to??CTR }
+              # 	      then { clockwise } else { anticlockwise }
+              # FROM	:: from boundaryatangle DIRN
+              # ++ {arrow @FromArrowLength arrowlength} atangle DIRN
+              # FROM	:< DIRN
+              # TO	:: to boundaryatangle { DIRN + 180d }
+              # ++ {arrow @ToArrowLength arrowlength} atangle { DIRN + 180d }
+              # TO	:< DIRN
+              #
+              # XP1	:= FROM ++ {fbias max 0} atangle DIRN
+              # XP4	:= TO ++ {tbias max 0} atangle { DIRN + 180d }
+              # YC	:= ycoord { from boundaryatangle 90d } max
+              # 	   ycoord { to   boundaryatangle 90d }
+              # 	   + { bias max 0 }
+              # XP2	:= { xcoord XP1 YC }
+              # XP3	:= { xcoord XP4 YC }
+              #
+              # RP1	:= radius min { XP1 distance FROM } min
+              # 	   { { XP1 distance XP2 } / 2 }
+              # XP1PRE	:= XP1 ++ RP1 atangle { XP1 angleto FROM }
+              # XP1POST := XP1 ++ RP1 atangle { XP1 angleto XP2  }
+              # XP1CTR  := XP1PRE ++ RP1 atangle { XP1 angleto XP2  }
+              # P1	:: XP1CTR ++ RP1 atangle { XP1CTR angleto XP1 }
+              # P1	:< XP1CTR angleto P1 + DIRN + 90d
+              #
+              # RP2	:= radius min { { XP1 distance XP2 } / 2 }
+              # 	     min { { XP2 distance XP3 } / 2 }
+              # XP2PRE	:= XP2 ++ RP2 atangle { XP2 angleto XP1 }
+              # XP2POST	:= XP2 ++ RP2 atangle { XP2 angleto XP3 }
+              # XP2CTR	:= XP2PRE ++ RP2 atangle { XP2 angleto XP3 }
+              # P2	:: XP2CTR ++ RP2 atangle { XP2CTR angleto XP2 }
+              # P2	:< XP2CTR angleto P2 + DIRN + 90d
+              #
+              # RP3	:= radius min { { XP2 distance XP3 } / 2 }
+              # 	     min { { XP3 distance XP4 } / 2 }
+              # XP3PRE	:= XP3 ++ RP3 atangle { XP3 angleto XP2 }
+              # XP3POST	:= XP3 ++ RP3 atangle { XP3 angleto XP4 }
+              # XP3CTR	:= XP3PRE ++ RP3 atangle { XP3 angleto XP4 }
+              # P3	:: XP3CTR ++ RP3 atangle { XP3CTR angleto XP3 }
+              # P3	:< XP3CTR angleto P3 + DIRN + 90d
+              #
+              # RP4	:= radius min { { XP4 distance XP3 } / 2 }
+              # 	     min { XP4 distance TO }
+              # XP4PRE	:= XP4 ++ RP4 atangle { XP4 angleto XP3 }
+              # XP4POST := XP4 ++ RP4 atangle { XP4 angleto TO  }
+              # XP4CTR  := XP4PRE ++ RP4 atangle { XP4 angleto TO  }
+              # P4	:: XP4CTR ++ RP4 atangle { XP4CTR angleto XP4 }
+              # P4	:< XP4CTR angleto P4 + DIRN + 90d
+              #
+              # XINDENT	:= xindent min { FROM distance XP1PRE }
+              # LFROM	:: FROM ++ XINDENT atangle DIRN
+              # LFROM	:< FROM@ANGLE
+              #
+              # LMID	:: XP2 ** 0.5 ++ XP3 ** 0.5
+              # LMID	:< DIRN - 180d
+              #
+              # ZINDENT	:= zindent min { TO distance XP4POST }
+              # LTO	:: TO ++ ZINDENT atangle { DIRN + 180d }
+              # LTO	:< TO@ANGLE
+              #
+              # FROM LFROM
+              # XP1PRE [XP1CTR CLOCK] XP1POST
+              # XP2PRE [XP2CTR CLOCK] XP2POST
+              # LMID
+              # XP3PRE [XP3CTR CLOCK] XP3POST
+              # XP4PRE [XP4CTR CLOCK] XP4POST
+              # LTO TO
+		  }
+		  PDF @Yield {}
+		}
+	    }
+
+	    import @Geometry
+	    def @Path
+	    {
+		path @Case {
+		    line			@Yield @LinePath
+		    doubleline			@Yield @DoubleLinePath
+		    { acurve curve }		@Yield @ACurvePath
+		    ccurve			@Yield @CCurvePath
+		    bezier			@Yield @BezierPath
+		    vhline			@Yield @VHLinePath
+		    vhcurve			@Yield @VHCurvePath
+		    hvline			@Yield @HVLinePath
+		    hvcurve			@Yield @HVCurvePath
+		    lvrline			@Yield @LVRLinePath
+		    lvrcurve			@Yield @LVRCurvePath
+		    rvlline			@Yield @RVLLinePath
+		    rvlcurve			@Yield @RVLCurvePath
+		    dwrapline			@Yield @DWrapLinePath
+		    dwrapcurve			@Yield @DWrapCurvePath
+		    uwrapline			@Yield @UWrapLinePath
+		    uwrapcurve			@Yield @UWrapCurvePath
+		    else			@Yield {
+			path
+			    from { from }
+			    to { to }
+			    bias { bias }
+			    fbias { fbias }
+			    tbias { tbias }
+			    radius { radius }
+			    xindent { xindent }
+			    zindent { zindent }
+			    frompt { frompt }
+			    topt { topt }
+			    arrow { arrow }
+			    arrowlength { arrowlength }
+		    }
+		}
+	    }
+
+	    def @FromLabel
+	    {
+		@DoLabel
+		    which	{ "f"				}
+		    label	{ fromlabel @Else @FromArrow	}
+		    labelmargin	{ fromlabelmargin		}
+		    labelfont	{ fromlabelfont			}
+		    labelbreak	{ fromlabelbreak		}
+		    labelformat { fromlabelformat @Body		}
+		    labelpos	{ fromlabelpos			}
+		    labelprox	{ fromlabelprox			}
+		    labelangle	{ fromlabelangle		}
+		    labelctr	{ fromlabelctr			}
+		    labeladjust	{ fromlabeladjust		}
+	    }
+
+	    def @ToLabel
+	    {
+		@DoLabel
+		    which	{ "t"				}
+		    label	{ tolabel @Else @ToArrow	}
+		    labelmargin	{ tolabelmargin			}
+		    labelfont	{ tolabelfont			}
+		    labelbreak	{ tolabelbreak			}
+		    labelformat { tolabelformat @Body		}
+		    labelpos	{ tolabelpos			}
+		    labelprox	{ tolabelprox			}
+		    labelangle	{ tolabelangle			}
+		    labelctr	{ tolabelctr			}
+		    labeladjust	{ tolabeladjust			}
+	    }
+
+	    def @Direct
+	    {
+		pathstyle @Case {
+		    { "/ldiagsolid" "/ldiagdashed" "/ldiagcdashed"
+		      "/ldiagdotted" "/ldiagnoline" } @Yield 1
+		    else @Yield 0
+		}
+	    }
+
+	  @BackEnd @Case {
+	    PostScript @Yield {
+
+	    @Null & # so that preceding space gets chewed up
+            {
+	      @Direct "ldiaglinkbegin [" @Path "]" pathdashlength
+	      "[" pathstyle "]" pathwidth "ldiaglinkend"
+            }
+            @Graphic
+            {
+		/ { fromlabel @Else @FromArrow}	@IfNonEmpty @FromLabel
+		/ { xlabel @Else linklabel }	@IfNonEmpty @XLabel
+		/ { ylabel @Else linklabel }	@IfNonEmpty @YLabel
+		/ { zlabel @Else linklabel }	@IfNonEmpty @ZLabel
+		/ { tolabel @Else @ToArrow }	@IfNonEmpty @ToLabel
+	    }
+
+	    }
+	    PDF @Yield {}
+	  }
+	}
+
+
+        def @ObjectLink
+	    precedence 90
+	    associativity left
+	    left x
+	    named treehsep { treehsep }
+	    named treevsep { treevsep }
+	    named format
+		named x {}
+		named y {}
+		named insinuatelink {}
+		named treehsep {}
+		named treevsep {}
+	    { x | y | insinuatelink }
+            import @Geometry named path
+                named from {}
+                named to {}
+                named bias {}
+                named fbias {}
+                named tbias {}
+                named radius {}
+                named xindent {}
+                named zindent {}
+                named frompt {}
+                named topt {}
+                named arrow {}
+                named arrowlength {}
+            					{ path
+						    from { from }
+						    to { to }
+						    bias { bias }
+						    fbias { fbias }
+						    tbias { tbias }
+						    radius { radius }
+						    xindent { xindent }
+						    zindent { zindent }
+						    frompt { frompt }
+						    topt { topt }
+						    arrow { arrow }
+						    arrowlength { arrowlength }
+						}
+            import @Geometry named basefrom	{ 			}
+            import @Geometry named baseto	{ 			}
+            import @Geometry named from		{ 			}
+            import @Geometry named to		{ 			}
+            import @Geometry named bias		{ bias			}
+            import @Geometry named fbias	{ fbias			}
+            import @Geometry named tbias	{ tbias			}
+            import @Geometry named radius	{ radius		}
+            import @Geometry named xindent	{ xindent		}
+            import @Geometry named zindent	{ zindent		}
+            import @Geometry named frompt	{ frompt		}
+            import @Geometry named topt		{ topt			}
+            named pathstyle
+		named solid   { "/ldiagsolid"   }
+		named dashed  { "/ldiagdashed"  }
+		named cdashed { "/ldiagcdashed" }
+		named dotted  { "/ldiagdotted"  }
+		named noline  { "/ldiagnoline"  }
+						{ pathstyle		}
+            import @Geometry named pathdashlength { pathdashlength	}
+            import @Geometry named pathwidth
+		named thin   { 0.04 ft }
+		named medium { 0.08 ft }
+		named thick  { 0.12 ft }
+						{ pathwidth		}
+            import @Geometry named pathgap
+		named thin   { 0.08 ft }
+		named medium { 0.16 ft }
+		named thick  { 0.24 ft }
+						{ pathgap		}
+
+            named arrow				{ arrow			}
+            named arrowstyle			{ arrowstyle		}
+            named arrowwidth			{ arrowwidth		}
+            named arrowlength			{ arrowlength		}
+
+	    named linklabel			{ linklabel		}
+	    named linklabelmargin		{ linklabelmargin	}
+	    named linklabelfont			{ linklabelfont		}
+	    named linklabelbreak		{ linklabelbreak	}
+	    named linklabelformat right @Body	{ linklabelformat @Body	}
+	    import @Geometry named linklabelpos	{ linklabelpos		}
+	    named linklabelprox			{ linklabelprox		}
+	    import @Geometry named linklabelangle  { linklabelangle	}
+	    named linklabelctr			{ linklabelctr		}
+	    import @Geometry named linklabeladjust { linklabeladjust	}
+
+            named xlabel			{ xlabel		}
+            named xlabelmargin	        	{ xlabelmargin		}
+            named xlabelfont			{ xlabelfont		}
+            named xlabelbreak			{ xlabelbreak		}
+	    named xlabelformat right @Body	{ xlabelformat @Body	}
+            import @Geometry named xlabelpos	{ xlabelpos		}
+            named xlabelprox			{ xlabelprox		}
+            import @Geometry named xlabelangle	{ xlabelangle		}
+	    named xlabelctr			{ xlabelctr		}
+            import @Geometry named xlabeladjust	{ xlabeladjust		}
+
+            named ylabel			{ ylabel		}
+            named ylabelmargin			{ ylabelmargin		}
+            named ylabelfont			{ ylabelfont		}
+            named ylabelbreak			{ ylabelbreak		}
+	    named ylabelformat right @Body	{ ylabelformat @Body	}
+            import @Geometry named ylabelpos	{ ylabelpos		}
+            named ylabelprox			{ ylabelprox		}
+            import @Geometry named ylabelangle	{ ylabelangle		}
+	    named ylabelctr			{ ylabelctr		}
+            import @Geometry named ylabeladjust	{ ylabeladjust		}
+
+            named zlabel			{ zlabel		}
+            named zlabelmargin			{ zlabelmargin		}
+            named zlabelfont			{ zlabelfont		}
+            named zlabelbreak			{ zlabelbreak		}
+	    named zlabelformat right @Body	{ zlabelformat @Body	}
+            import @Geometry named zlabelpos	{ zlabelpos		}
+            named zlabelprox			{ zlabelprox		}
+            import @Geometry named zlabelangle	{ zlabelangle		}
+	    named zlabelctr			{ zlabelctr		}
+            import @Geometry named zlabeladjust	{ zlabeladjust		}
+
+            named fromlabel			{ fromlabel		}
+            named fromlabelmargin		{ fromlabelmargin	}
+            named fromlabelfont			{ fromlabelfont		}
+            named fromlabelbreak		{ fromlabelbreak	}
+	    named fromlabelformat right @Body	{ fromlabelformat @Body	}
+            import @Geometry named fromlabelpos	{ fromlabelpos		}
+            named fromlabelprox			{ fromlabelprox		}
+            import @Geometry named fromlabelangle  { fromlabelangle	}
+	    named fromlabelctr			{ fromlabelctr		}
+            import @Geometry named fromlabeladjust { fromlabeladjust	}
+
+            named tolabel			{ tolabel		}
+            named tolabelmargin			{ tolabelmargin		}
+            named tolabelfont			{ tolabelfont		}
+            named tolabelbreak			{ tolabelbreak		}
+	    named tolabelformat right @Body	{ tolabelformat @Body	}
+            import @Geometry named tolabelpos	{ tolabelpos		}
+            named tolabelprox			{ tolabelprox		}
+            import @Geometry named tolabelangle	{ tolabelangle		}
+	    named tolabelctr			{ tolabelctr		}
+            import @Geometry named tolabeladjust{ tolabeladjust		}
+	    right y
+
+        {
+	    def @From
+	    {
+		from @Case {
+		    ""   @Yield basefrom
+		    else @Yield { basefrom"@"from }
+		}
+	    }
+
+	    def @To
+	    {
+		to @Case {
+		    ""   @Yield baseto
+		    else @Yield { baseto"@"to }
+		}
+	    }
+
+	    format
+		x { x }
+		y { y }
+		treehsep { treehsep }
+		treevsep { treevsep }
+		insinuatelink {
+		    @Link
+			from		{ @From			}
+			to		{ @To			}
+			bias		{ bias			}
+			fbias		{ fbias			}
+			tbias		{ tbias			}
+			radius		{ radius		}
+			xindent		{ xindent		}
+			zindent		{ zindent		}
+			frompt		{ frompt		}
+			topt		{ topt			}
+			path		{ path
+						from { @From }
+						to { @To }
+						bias { bias }
+						fbias { fbias }
+						tbias { tbias }
+						radius { radius }
+						xindent { xindent }
+						zindent { zindent }
+						frompt { frompt }
+						topt { topt }
+						arrow { arrow }
+						arrowlength { arrowlength }
+					}
+			pathstyle	{ pathstyle		}
+			pathdashlength	{ pathdashlength	}
+			pathwidth	{ pathwidth		}
+			pathgap 	{ pathgap		}
+			arrow		{ arrow			}
+			arrowstyle	{ arrowstyle		}
+			arrowwidth	{ arrowwidth		}
+			arrowlength	{ arrowlength		}
+
+			linklabel	{ linklabel		}
+			linklabelmargin	{ linklabelmargin	}
+			linklabelfont	{ linklabelfont		}
+			linklabelbreak	{ linklabelbreak	}
+			linklabelformat	{ linklabelformat @Body	}
+			linklabelpos	{ linklabelpos		}
+			linklabelprox	{ linklabelprox		}
+			linklabelangle	{ linklabelangle	}
+			linklabelctr	{ linklabelctr		}
+			linklabeladjust	{ linklabeladjust	}
+
+			xlabel		{ xlabel		}
+			xlabelmargin	{ xlabelmargin		}
+			xlabelfont	{ xlabelfont		}
+			xlabelbreak	{ xlabelbreak		}
+			xlabelformat	{ xlabelformat @Body	}
+			xlabelpos	{ xlabelpos		}
+			xlabelprox	{ xlabelprox		}
+			xlabelangle	{ xlabelangle		}
+			xlabelctr	{ xlabelctr		}
+			xlabeladjust	{ xlabeladjust		}
+
+			ylabel		{ ylabel		}
+			ylabelmargin	{ ylabelmargin		}
+			ylabelfont	{ ylabelfont		}
+			ylabelbreak	{ ylabelbreak		}
+			ylabelformat	{ ylabelformat @Body	}
+			ylabelpos	{ ylabelpos		}
+			ylabelprox	{ ylabelprox		}
+			ylabelangle	{ ylabelangle		}
+			ylabelctr	{ ylabelctr		}
+			ylabeladjust	{ ylabeladjust		}
+
+			zlabel		{ zlabel		}
+			zlabelmargin	{ zlabelmargin		}
+			zlabelfont	{ zlabelfont		}
+			zlabelbreak	{ zlabelbreak		}
+			zlabelformat	{ zlabelformat @Body	}
+			zlabelpos	{ zlabelpos		}
+			zlabelprox	{ zlabelprox		}
+			zlabelangle	{ zlabelangle		}
+			zlabelctr	{ zlabelctr		}
+			zlabeladjust	{ zlabeladjust		}
+
+			fromlabel	{ fromlabel		}
+			fromlabelmargin	{ fromlabelmargin	}
+			fromlabelfont	{ fromlabelfont		}
+			fromlabelbreak	{ fromlabelbreak	}
+			fromlabelformat	{ fromlabelformat @Body	}
+			fromlabelpos	{ fromlabelpos		}
+			fromlabelprox	{ fromlabelprox		}
+			fromlabelangle	{ fromlabelangle	}
+			fromlabelctr	{ fromlabelctr		}
+			fromlabeladjust	{ fromlabeladjust	}
+
+			tolabel		{ tolabel		}
+			tolabelmargin	{ tolabelmargin		}
+			tolabelfont	{ tolabelfont		}
+			tolabelbreak	{ tolabelbreak		}
+			tolabelformat	{ tolabelformat @Body	}
+			tolabelpos	{ tolabelpos		}
+			tolabelprox	{ tolabelprox		}
+			tolabelangle	{ tolabelangle		}
+			tolabelctr	{ tolabelctr		}
+			tolabeladjust	{ tolabeladjust		}
+	    }
+        }
+
+	macro @Line		{ @Link path { line     }		}
+	macro @DoubleLine	{ @Link path { doubleline }		}
+	macro @Arrow		{ @Link path { line     } arrow { yes }	}
+	macro @DoubleArrow	{ @Link path {doubleline} arrow { yes }	}
+	macro @Curve		{ @Link path { curve	}		}
+	macro @CurveArrow	{ @Link path { curve	} arrow { yes }	}
+	macro @ACurve		{ @Link path { acurve	}		}
+	macro @ACurveArrow	{ @Link path { acurve	} arrow { yes }	}
+	macro @CCurve		{ @Link path { ccurve	}		}
+	macro @CCurveArrow	{ @Link path { ccurve	} arrow { yes }	}
+
+	macro @Bezier		{ @Link path { bezier	}		}
+	macro @BezierArrow	{ @Link path { bezier	} arrow { yes }	}
+
+	macro @HVLine		{ @Link path { hvline   }		}
+	macro @HVArrow		{ @Link path { hvline   } arrow { yes }	}
+	macro @VHLine		{ @Link path { vhline   }		}
+	macro @VHArrow		{ @Link path { vhline   } arrow { yes }	}
+	macro @HVCurve		{ @Link path { hvcurve  }		}
+	macro @HVCurveArrow	{ @Link path { hvcurve  } arrow { yes }	}
+	macro @VHCurve		{ @Link path { vhcurve  }		}
+	macro @VHCurveArrow	{ @Link path { vhcurve  } arrow { yes }	}
+
+	macro @LVRLine		{ @Link path { lvrline  }		}
+	macro @LVRArrow		{ @Link path { lvrline  } arrow { yes }	}
+	macro @RVLLine		{ @Link path { rvlline  }		}
+	macro @RVLArrow		{ @Link path { rvlline  } arrow { yes }	}
+	macro @LVRCurve		{ @Link path { lvrcurve }		}
+	macro @LVRCurveArrow	{ @Link path { lvrcurve } arrow { yes }	}
+	macro @RVLCurve		{ @Link path { rvlcurve }		}
+	macro @RVLCurveArrow	{ @Link path { rvlcurve } arrow { yes }	}
+
+	macro @DWrapLine	{ @Link path { dwrapline}		}
+	macro @DWrapArrow	{ @Link path { dwrapline} arrow { yes }	}
+	macro @UWrapLine	{ @Link path { uwrapline}		}
+	macro @UWrapArrow	{ @Link path { uwrapline} arrow { yes }	}
+	macro @DWrapCurve	{ @Link path {dwrapcurve}		}
+	macro @DWrapCurveArrow	{ @Link path {dwrapcurve} arrow { yes }	}
+	macro @UWrapCurve	{ @Link path {uwrapcurve}		}
+	macro @UWrapCurveArrow	{ @Link path {uwrapcurve} arrow { yes }	}
+
+	export
+
+	    @Node @Box @CurveBox @ShadowBox @Square @Diamond
+	    @Polygon @Isosceles @Ellipse @Circle
+	    @LeftSub @ZeroWidthLeftSub @RightSub @ZeroWidthRightSub
+	    @FirstSub @NextSub @StubSub
+
+	def @Tree
+	    named treehindent
+		named left  { 0.0rt }
+		named ctr   { 0.5rt }
+		named right { 1.0rt }
+						{ treehindent		}
+	    body x
+	{
+
+	    macro @TNode	{ @@Node nodetag { T 		} }
+            macro @Node		{ @TNode                          }
+            macro @Box		{ @TNode outline { box		} }
+            macro @CurveBox	{ @TNode outline { curvebox	} }
+	    macro @ShadowBox	{ @TNode outline { shadowbox	} }
+            macro @Square	{ @TNode outline { square	} }
+            macro @Diamond	{ @TNode outline { diamond	} }
+            macro @Polygon	{ @TNode outline { polygon	} }
+            macro @Isosceles	{ @TNode outline { isosceles	} }
+            macro @Ellipse	{ @TNode outline { ellipse	} }
+            macro @Circle	{ @TNode outline { circle	} }
+
+	    def fixroot
+		precedence 90
+		left root
+	    {
+		|treehindent root
+	    }
+
+	    macro @LeftSub
+	    {
+		@ObjectLink
+		    basefrom { T }
+		    baseto { L@T }
+		    format { { /treevsep {L::y} } |treehsep x | insinuatelink }
+	    }
+
+	    macro @ZeroWidthLeftSub
+	    {
+		@ObjectLink
+		    basefrom { T }
+		    baseto { L@T }
+		    format { { /treevsep @ZeroWidth { {L::y} ^|treehsep } } |
+			x | insinuatelink }
+	    }
+
+	    macro @FirstSub
+	    {
+		fixroot //
+		@ObjectLink
+		    basefrom { T }
+		    baseto { S@T }
+		    format { //treevsep {S::y} | insinuatelink | }
+	    }
+
+	    macro @NextSub
+	    {
+		@ObjectLink
+		    basefrom { T }
+		    baseto { S@T }
+		    format { x |treehsep { / {S::y} | insinuatelink | } }
+	    }
+
+	    macro @RightSub
+	    {
+		@ObjectLink
+		    basefrom { T }
+		    baseto { R@T }
+		    format { x |treehsep  { /treevsep {R::y} } | insinuatelink }
+	    }
+
+	    macro @ZeroWidthRightSub
+	    {
+		@ObjectLink
+		    basefrom { T }
+		    baseto { R@T }
+		    format { x | { /treevsep @ZeroWidth { |treehsep {R::y} } }
+			| insinuatelink }
+	    }
+
+	    macro @StubSub
+	    {
+		@ObjectLink
+		    basefrom { T }
+		    baseto { T }
+		    format { @VContract { |0.5rt x | // |0.5rt
+		      S:: @BoxLabels @CatchTags y | } | insinuatelink }
+		    # path { from S@T@SW S@T@SE to }
+		    path {
+			P1::	S@SW
+			P2::	S@SE
+			FROM::	from boundaryatangle { from??CTR angleto P1 }
+			TO::	to   boundaryatangle { to??CTR   angleto P2 }
+			FROM P1 P2 TO
+		    }
+	    }
+
+	    @HContract @VContract x
+	}
+
+	export
+
+	    @Node @Box @CurveBox @ShadowBox @Square @Diamond
+	    @Polygon @Isosceles @Ellipse @Circle
+	    @LeftSub @ZeroWidthLeftSub @RightSub @ZeroWidthRightSub
+	    @FirstSub @NextSub @StubSub
+
+	def @HTree
+	    named treevindent
+		named top   { 0.0rt }
+		named ctr   { 0.5rt }
+		named foot  { 1.0rt }
+						{ treevindent		}
+	    body x
+	{
+
+	    macro @TNode	{ @@Node nodetag { T 		} }
+	    macro @Node		{ @TNode                          }
+            macro @Box		{ @TNode outline { box		} }
+            macro @CurveBox	{ @TNode outline { curvebox	} }
+	    macro @ShadowBox	{ @TNode outline { shadowbox	} }
+            macro @Square	{ @TNode outline { square	} }
+            macro @Diamond	{ @TNode outline { diamond	} }
+            macro @Polygon	{ @TNode outline { polygon	} }
+            macro @Isosceles	{ @TNode outline { isosceles	} }
+            macro @Ellipse	{ @TNode outline { ellipse	} }
+            macro @Circle	{ @TNode outline { circle	} }
+
+	    def fixroot
+		precedence 90
+		left root
+	    {
+		/treevindent root
+	    }
+
+	    macro @LeftSub
+	    {
+		@ObjectLink
+		    basefrom { T }
+		    baseto { L@T }
+		    format { { |treehsep {L::y} } /treevsep x / insinuatelink }
+	    }
+
+	    macro @ZeroWidthLeftSub
+	    {
+		@ObjectLink
+		    basefrom { T }
+		    baseto { L@T }
+		    format { { |treehsep @ZeroWidth { {L::y} ^/treevsep } } /
+			x / insinuatelink }
+	    }
+
+	    macro @FirstSub
+	    {
+		fixroot ||
+		@ObjectLink
+		    basefrom { T }
+		    baseto { S@T }
+		    format { ||treehsep { {S::y} / insinuatelink / } }
+	    }
+
+	    macro @NextSub
+	    {
+		@ObjectLink
+		    basefrom { T }
+		    baseto { S@T }
+		    format { x /treevsep { | {S::y} { / insinuatelink / } } }
+	    }
+
+	    macro @RightSub
+	    {
+		@ObjectLink
+		    basefrom { T }
+		    baseto { R@T }
+		    format { x /treevsep  { |treehsep {R::y} } / insinuatelink }
+	    }
+
+	    macro @ZeroWidthRightSub
+	    {
+		@ObjectLink
+		    basefrom { T }
+		    baseto { R@T }
+		    format { x / { |treehsep @ZeroWidth { /treevsep {R::y} } }
+			/ insinuatelink }
+	    }
+
+	    macro @StubSub
+	    {
+		@ObjectLink
+		    basefrom { T }
+		    baseto { T }
+		    format { @VContract { { /0.5rt x / } || { /0.5rt
+		      S:: @BoxLabels @CatchTags y / } } / insinuatelink }
+		    # path { from S@T@SW S@T@SE to }
+		    path {
+			P1::	S@NE
+			P2::	S@SE
+			FROM::	from boundaryatangle { from??CTR angleto P1 }
+			TO::	to   boundaryatangle { to??CTR   angleto P2 }
+			FROM P1 P2 TO
+		    }
+	    }
+
+	    @HContract @VContract x
+	}
+
+	@BackEnd @Case {
+	  PostScript @Yield {
+        {
+	  save @Case { { yes Yes } @Yield "grestore save gsave" else @Yield {} }
+	  maxlabels "ldiagbegin"
+          //
+	  "ldiagend"
+	  save @Case { { yes Yes } @Yield "restore" else @Yield {} }
+        } @Graphic @Body
+	  }
+	  PDF @Yield {}
+	}
+
+    @End @Diag
+}