Deleting Things

All of these operations are non-monotonic, and should only be used with great care.

(:delete  atomic-formula)
Removes atomic-formula from the knowledge-base.

(:clear-slot  fterm slot)
Removes all values from slot slot of the frame referred to by fterm.

(:del-rule  fterm rule)

(:del-srule  fterm rule)
Used to delete a rule (or slot rule) from a frame.

(:del-rules  fterm slot)

(:del-srules  fterm slot)
Used to delete all rules (or slot rules) from a slot of a frame.