tauto
v t : VarName
phi : Formula
phi_ih : ∀ (binders : Finset VarName), v ∉ binders → replaceFreeAux v t binders phi = fastReplaceFree v t phi
binders : Finset VarName
h1 : v ∉ binders
⊢ (replaceFreeAux v t binders phi).not_ = (fastReplaceFree v t phi).not_
no goals