infocom/compilers/inform5/library/contributions/use.h

! Use           An Inform 5.5 library extention by L. Ross Raszewski
!
! Adds a handy USE verb.

! I don't know if this is the best way to do this, but it seems to work
[ SOnAble; if (noun has switchable && noun hasnt on) rtrue; rfalse;];
[ SOffAble; if (noun has switchable && noun has on) rtrue; rfalse;];
[ OpenUpAble; if (noun has openable && noun hasnt open) rtrue; rfalse;];
[ CloseUpAble; if (noun has openable && noun has open) rtrue; rfalse;];

Verb "use" "employ" "utilise" "utilize"
                                * edible                        ->Eat
                                * clothing                      ->Wear
                                * enterable                     ->Enter
                                * door                          ->Enter
                                * noun=SOnAble                  ->switchon
                                * noun=SOffAble                 ->switchoff
                                * noun=OpenUpAble               ->Open
                                * noun=CloseUpAble              ->Close;