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