rename_i originalWidth
case signExtend
w : Nat
assign : Assignment
w✝ v : Nat
inner : BVExpr w✝
ih :
  ∀ (aig : AIG BVBit) (idx : Nat) (hidx : idx < w✝),
    ⟦{ aig := (go aig inner).val.aig, ref := (go aig inner).val.stream.getRef idx hidx }, assign.toAIGAssignment⟧ =
      (eval assign inner).getLsb idx
aig : AIG BVBit
idx : Nat
hidx : idx < v
⊢ ⟦{ aig := (go aig (signExtend v inner)).val.aig, ref := (go aig (signExtend v inner)).val.stream.getRef idx hidx },
      assign.toAIGAssignment⟧ =
    (eval assign (signExtend v inner)).getLsb idx
case signExtend
w : Nat
assign : Assignment
originalWidth v : Nat
inner : BVExpr originalWidth
ih :
  ∀ (aig : AIG BVBit) (idx : Nat) (hidx : idx < originalWidth),
    ⟦{ aig := (go aig inner).val.aig, ref := (go aig inner).val.stream.getRef idx hidx }, assign.toAIGAssignment⟧ =
      (eval assign inner).getLsb idx
aig : AIG BVBit
idx : Nat
hidx : idx < v
⊢ ⟦{ aig := (go aig (signExtend v inner)).val.aig, ref := (go aig (signExtend v inner)).val.stream.getRef idx hidx },
      assign.toAIGAssignment⟧ =
    (eval assign (signExtend v inner)).getLsb idx