simp only [def_and_]
case h1.h2.a.a
P Q : Formula
v : VarName
⊢ IsDeduct ({exists_ v (P.and_ Q)} ∪ {P.and_ Q})
    ((exists_ v P).imp_ ((exists_ v Q).imp_ ((exists_ v P).and_ (exists_ v Q))))
case h1.h2.a.a
P Q : Formula
v : VarName
⊢ IsDeduct ({exists_ v (P.imp_ Q.not_).not_} ∪ {(P.imp_ Q.not_).not_})
    ((exists_ v P).imp_ ((exists_ v Q).imp_ ((exists_ v P).imp_ (exists_ v Q).not_).not_))