@Section
   @Title { Getting started }
@Begin
@PP
The Lout definitions for the @Code "@Math" symbol are accessed via a setup
file called {@Code "math"}, which you must include at the start of your
document if
math.file @Index { @Code "math" file }
you want mathematics, like this:
@ID @OneRow @Code {
"@SysInclude { tbl }"
"@SysInclude { math }"
"@SysInclude { doc }"
"@Doc @Text @Begin"
"..."
"@End @Text"
}
This shows what to do if you want both tables and mathematics, but you
may leave out the line for tables if you don't want them.  Setup files
for specialized packages, such as {@Code "tbl"} and {@Code "math"},
are best included before the main setup file, but may be included in
any order.
@PP
With the @Code "math" file included, you may write
@ID @Code "@Math { ... }"
at any point in your document, and the symbols of @Code "@Math" will be
available between the braces.  Any symbols available outside continue
to be available inside, which means that mathematics may be freely mixed
with other symbols.
@PP
The @Code "@Math" symbol may appear anywhere; its job is to produce
an object containing mathematics, and it neither knows nor cares where
that object goes.  To display mathematics, use a display symbol
like @Code "@IndentedDisplay" or @Code "@CentredDisplay"
(Section {@NumberOf displays}).  For example,
@ID @Code "@CentredDisplay @Math { int from { 0 } to { pi } sin ` x = 0 }"
produces
@CentredDisplay @Math { int from { 0 } to { pi } sin ` x = 0 }
There are also symbols for aligned and numbered displays
(Section {@NumberOf mathdisplays}).
@PP
The @Code "@Math" symbol sets the mathematics in @I { display style },
mathematics.display.style @SubIndex { display style }
display.style @Index { display style (mathematics) }
a style suited to displays.  To get mathematics within a paragraph,
it is best to use a variant of @Code "@Math" called {@Code "@M"}.  The
mathematics.maaa @SubIndex { @Code "@M" }
maaa. @Index { @Code "@M" (mathematics) }
value of @Code "@M { ... }" will be kept together on one line, and it
will appear in @I { text style }, a more compact style suited to
mathematics.text.style @SubIndex { text style }
text.style @Index { text style (mathematics) }
mathematics within paragraphs.
@PP
Throughout this chapter we show the Lout input at the left, and its
result at the right:
@ID {
@Code "@Math { {x sup 2 + y sup 2} over 2 }"
|7ct
@Math { {x sup 2 + y sup 2} over 2 }
}
Subsequent examples will omit the enclosing {@Code "@Math { ... }"}.
@End @Section