simp only [def_and_]
case h3
P : Formula
v : VarName
⊢ IsDeduct ∅ (((forall_ v P).imp_ (forall_ v P).not_.not_).and_ ((forall_ v P).not_.not_.imp_ (forall_ v P)))
case h3
P : Formula
v : VarName
⊢ IsDeduct ∅ (((forall_ v P).imp_ (forall_ v P).not_.not_).imp_ ((forall_ v P).not_.not_.imp_ (forall_ v P)).not_).not_