simp
case bin.add.hleft
w : Nat
assign : Assignment
w✝ : Nat
lhs rhs : BVExpr w✝
lih :
  ∀ (aig : AIG BVBit) (idx : Nat) (hidx : idx < w✝),
    ⟦{ aig := (go aig lhs).val.aig, ref := (go aig lhs).val.stream.getRef idx hidx }, assign.toAIGAssignment⟧ =
      (eval assign lhs).getLsb idx
rih :
  ∀ (aig : AIG BVBit) (idx : Nat) (hidx : idx < w✝),
    ⟦{ aig := (go aig rhs).val.aig, ref := (go aig rhs).val.stream.getRef idx hidx }, assign.toAIGAssignment⟧ =
      (eval assign rhs).getLsb idx
aig : AIG BVBit
idx : Nat
hidx : idx < w✝
idx✝ : Nat
hidx✝ : idx✝ < w✝
⊢ ⟦{ aig := (go aig lhs).1.aig,
        ref := { gate := (((go aig lhs).1.stream.cast ⋯).getRef idx✝ hidx✝).gate, hgate := ?bin.add.hleft.hstart } },
      assign.toAIGAssignment⟧ =
    ⟦{ aig := (go aig lhs).val.aig, ref := (go aig lhs).val.stream.getRef idx✝ ?bin.add.hleft.hidx },
      assign.toAIGAssignment⟧
no goals