@Section
   @Title { Aligned columns }
@Begin
@PP
Columns of numbers are often presented with decimal points aligned:
@CD @Tab
    @Fmta { @Col A }
{
    @Rowa A { 5^.46 }
    @Rowa A { 128^.2 }
    @Rowa A { 3^.4159 }
    @Rowa A { 5772^ }
}
This is achieved with Tab by placing the @Code "^" symbol (which
actually comes from the DocumentLayout package) just before the
alignment point in each entry:
@ID @Code {
"@Tab"
"    @Fmta { @Col A }"
"{"
"    @Rowa A { 5^.46 }"
"    @Rowa A { 128^.2 }"
"    @Rowa A { 3^.4159 }"
"    @Rowa A { 5772^ }"
"}"
}
The equals signs of equations can be aligned in the same way.  The
format of such columns should not contain @Code "@CC" or {@Code "@RR"}.
@PP
The simplest way to get a heading over an aligned column is to use the
@Code "^" symbol in the heading as well.  If it is not possible to do
this, for example because the heading entry is a paragraph of text
broken over more than one line, the most viable alternative is to use
@Code "@Over" in the heading line's format to make the heading column
span over the aligned column:
@ID @Code {
"@Tab"
"    @Fmta { @Col @CC H @Over A }"
"    @Fmtb { @Col A }"
"{"
"    @Rowa H { Heading }"
"    @Rowb A { 5^.46 }"
"    @Rowb A { 128^.2 }"
"    @Rowb A { 3^.4159 }"
"    @Rowb A { 5772^ }"
"}"
}
for example produces
@CD @Tab
    @Fmta { @Col @CC H @Over A }
    @Fmtb { @Col A }
{
    @Rowa H { Heading }
    @Rowb A { 5^.46 }
    @Rowb A { 128^.2 }
    @Rowb A { 3^.4159 }
    @Rowb A { 5772^ }
}
Unfortunately, the aligned entries are left-justified in the column, when
they should really be centred.
@End @Section
