constructor
α : Type u_1
inst✝ : DecidableEq α
p : Formula α
⊢ 𝐒𝟒 ⊢! p ↔ 𝐊𝟒 ⊢! pᵇ
case mp
α : Type u_1
inst✝ : DecidableEq α
p : Formula α
⊢ 𝐒𝟒 ⊢! p → 𝐊𝟒 ⊢! pᵇ

case mpr
α : Type u_1
inst✝ : DecidableEq α
p : Formula α
⊢ 𝐊𝟒 ⊢! pᵇ → 𝐒𝟒 ⊢! p