The backward chaining inference engine is started to look for any set of bindings which satisfy goal-to-prove . Using those bindings, pattern-to-instantiate is instantiated and returned.
Two values are returned. The second value indicates with
t
that a proof was found, or with
nil
that no proof exists. In the former case, the first value is the instantiated version of
pattern-to-instantiate
, in the latter case, the first value is
nil
.
Any subgoals that match the object base will only find objects from the current inferencing state.