Remove redundant antecedents from expanded variables in predicate position

[fcbr]

When expanding:

(=>
   (instance ?REL SymmetricRelation)
   (forall (?INST1 ?INST2)
      (=>
         (?REL ?INST1 ?INST2)
         (?REL ?INST2 ?INST1))))

we will generate, for example, this:

(=>
   (instance inverse SymmetricRelation)
   (forall (?INST1 ?INST2)
      (=>
         (inverse ?INST1 ?INST2)
         (inverse ?INST2 ?INST1))))

However, the outer antecedent is not needed, since it is already a fact declared in Merge.kif. We don't need to create an implication that always evaluate the consequent. The end formula would be simply:

(forall (?INST1 ?INST2)
   (=>
      (inverse ?INST1 ?INST2)
      (inverse ?INST2 ?INST1)))