2.2 Slide Registration
procedure
Returns a slide structure that may be supplied to re-slide to make a
copy of the slide or slide->pict to re-extract the entire
slide as a pict.
procedure
Cancels the most recently created slide, and also returns a slide
structure that may be supplied to re-slide to restore the slide
(usually in a later position).
Re-inserts a slide, lt-superimposeing the given additional
pict.
procedure
(slide->pict slide) → pict?
slide : slide?
Converts a complete slide to a pict. The bounding box of the
result corresponds to the slide within its margins.