Builds a composite from
one or more
GTL-statements.
The composite could be an entire graph. Or, if this layout is nested
in another layout, such as a GRIDDED layout, the composite typically
provides contents for one cell in the parent layout. In an OVERLAYEQUATED
layout, the display unit of the X axis always equals the display unit
of the Y axis.
LAYOUT OVERLAYEQUATED </option(s)>;
GTL-statements;
ENDLAYOUT;