The menu command is captured by lines similar to the following
%.menu&: xtpanel -cpp -var mechanism cake -var name % -DINTERACT \ -file builder.xt panel >&/dev/null &xtpanel is a graphical user interface scripting language which was created by Steve Cole and Dave Nichols 1992. We rely heavily on it for interacting with the readers of interactive documents. The menu will have REBUILD and BURN buttons if the figure is rebuildable. A figure is judged rebuildable if the cakefile can generate the file FIGDIR/%.ps. The command cake NAME.burn is issued by pressing the BURN button and pressing the REBUILD button issues the command cake NAME.ps If the figure is not rebuildable those buttons are inactive on the screen menu.
The menu will have an inactive INTERACTION button in case the author does not provide some interaction. An default interaction is possible if there exists one or more of the following: