delete a logical transistor
int dellotrs(ptfig, pttrs)
Pointer to the figure in which the transistor should be deleted
Pointer to the transistor to be deleted.
dellotrs delete the transistor pointed to by pttrs in the figure
pointed to by ptfig.
The list consistency is maintainded, and the space freed. The transistor
connectors are also freed, since if the transistor disapear,
no more connections can occur on it.
dellotrs returns 1 if the transistor has been deleted, 0
if the transistor pointer does nit exists in the list.
char *was_existing(ptfig, pttrs)
return dellotrs(ptfig, pttrs) ? "you just killed it!"
: "wasn't here anyway";