multiple layouts that are on compatible screens.
@end deffn
-@deffn Procedure set-fix-layout-size! layout width height
-Sets @var{layout} to the given @var{width} and @var{height}. If
-either dimension is -1, that dimension is unset, allowing @var{layout}
-to choose a "natural" size --- large enough to lay out the entire
-text. If a dimension is 0, it is treated like 1, which means ``as
-small as possible'', e.g. one line or one column.
-@end deffn
-
@deffn Procedure fix-layout-scroll-step layout
A pair: the horizontal and vertical scroll increments. It is shared
with @var{layout}; do not modify it.