cases hclause2 with
| inl hl => exact Exists.intro _ hl
| inr hr => exact Exists.intro _ hr
case mpr.intro.intro.intro.right
α : Type
g : CNF α
lit : α
clause : Clause α
hclause1 : clause ∈ g
hclause2 : (lit, false) ∈ clause ∨ (lit, true) ∈ clause
⊢ ∃ x, x ∈ clause
no goals