apply IsReplOfFormulaInFormula.same_
case h1.a
P Q : Formula
v : VarName
h1 : ¬isFreeIn v P
⊢ IsReplOfFormulaInFormula (forall_ v P) P (forall_ v (P.imp_ Q)) (forall_ v (P.imp_ Q))
case h1.a.a
P Q : Formula
v : VarName
h1 : ¬isFreeIn v P
⊢ forall_ v (P.imp_ Q) = forall_ v (P.imp_ Q)