simp [h] at heval2
aig : AIG Nat
start : Nat
h1 : start < aig.decls.size
assign : aig.CNFVar → Bool
h : ⟦{ aig := aig, ref := { gate := start, hgate := h1 } }, projectLeftAssign assign⟧ = false
heval1 : CNF.eval assign (go aig start h1 (State.empty aig)).val.cnf = true
heval2 :
  ⟦{ aig := aig, ref := { gate := start, hgate := h1 } }, projectLeftAssign assign⟧ = projectRightAssign assign start h1
⊢ CNF.eval assign ([(Sum.inr ⟨start, h1⟩, true)] :: (go aig start h1 (State.empty aig)).val.cnf) = false
aig : AIG Nat
start : Nat
h1 : start < aig.decls.size
assign : aig.CNFVar → Bool
h : ⟦{ aig := aig, ref := { gate := start, hgate := h1 } }, projectLeftAssign assign⟧ = false
heval1 : CNF.eval assign (go aig start h1 (State.empty aig)).val.cnf = true
heval2 : assign (Sum.inr ⟨start, h1⟩) = false
⊢ CNF.eval assign ([(Sum.inr ⟨start, h1⟩, true)] :: (go aig start h1 (State.empty aig)).val.cnf) = false