. split
  . next heq =>
    simp only [heq, negateLiteral, not, ne_eq, Prod.mk.injEq, true_and] at negl_ne_v
    split at negl_ne_v <;> simp_all
  . next hne =>
    exact pv
case intro.inr.intro.intro.h.right
n : Nat
p : PosFin n → Bool
c : DefaultClause n
l : Literal (PosFin n)
v : PosFin n
pv : p v = true
negl_ne_v : (v, true) ≠ l.negateLiteral
v_in_c_del_l : (v, true) ∈ c.toList
⊢ (if v = l.fst then l.snd else p v) = true
no goals