exact t.not_mem₂_iff_mem₁.mp $ not_mem₂ (by simpa) (show 𝓓 ⊢! List.conj' [p] ⟶ q by simpa;)
α : Type u_1
inst✝³ : DecidableEq α
inst✝² : Inhabited α
𝓓 : DeductionParameter α
inst✝¹ : 𝓓.IncludeEFQ
inst✝ : Encodable α
t✝ t t₁ t₂ : SCT 𝓓
p q : Formula α
hp : p ∈ t.tableau.1
h : 𝓓 ⊢! p ⟶ q
⊢ q ∈ t.tableau.1
no goals