-- Mathlib/.lake/packages/lean4/src/lean/Std/Tactic/BVDecide/Bitblast/BVExpr/Circuit/Lemmas/Expr.lean
theorem go_denote_eq (aig : AIG BVBit) (expr : BVExpr w) (assign : Assignment) :
    ∀ (idx : Nat) (hidx : idx < w),
        ⟦(go aig expr).val.aig, (go aig expr).val.vec.get idx hidx, assign.toAIGAssignment⟧
          =
        (expr.eval assign).getLsbD idx

Proof state:
case signExtend
w : Nat
assign : Assignment
originalWidth v : Nat
inner : BVExpr originalWidth
ih :
  ∀ (aig : AIG BVBit) (idx : Nat) (hidx : idx < originalWidth),
    ⟦assign.toAIGAssignment, { aig := (go aig inner).val.aig, ref := (go aig inner).val.vec.get idx hidx }⟧ =
      (eval assign inner).getLsbD idx
aig : AIG BVBit
idx : Nat
hidx : idx < v
res : RefVecEntry BVBit v
hgo : blastSignExtend (go aig inner).1.aig { w := originalWidth, vec := (go aig inner).1.vec } = res
⊢ ⟦assign.toAIGAssignment, { aig := res.aig, ref := res.vec.get idx hidx }⟧ =
    (eval assign (signExtend v inner)).getLsbD idx

Tactic:
have : 0 ≤ originalWidth := by omega

Result:
case signExtend
w : Nat
assign : Assignment
originalWidth v : Nat
inner : BVExpr originalWidth
ih :
  ∀ (aig : AIG BVBit) (idx : Nat) (hidx : idx < originalWidth),
    ⟦assign.toAIGAssignment, { aig := (go aig inner).val.aig, ref := (go aig inner).val.vec.get idx hidx }⟧ =
      (eval assign inner).getLsbD idx
aig : AIG BVBit
idx : Nat
hidx : idx < v
res : RefVecEntry BVBit v
hgo : blastSignExtend (go aig inner).1.aig { w := originalWidth, vec := (go aig inner).1.vec } = res
this : 0 ≤ originalWidth
⊢ ⟦assign.toAIGAssignment, { aig := res.aig, ref := res.vec.get idx hidx }⟧ =
    (eval assign (signExtend v inner)).getLsbD idx

Proof state:
case shiftRight.hleft
w : Nat
assign : Assignment
m✝ n✝ : Nat
lhs : BVExpr m✝
rhs : BVExpr n✝
lih :
  ∀ (aig : AIG BVBit) (idx : Nat) (hidx : idx < m✝),
    ⟦assign.toAIGAssignment, { aig := (go aig lhs).val.aig, ref := (go aig lhs).val.vec.get idx hidx }⟧ =
      (eval assign lhs).getLsbD idx
rih :
  ∀ (aig : AIG BVBit) (idx : Nat) (hidx : idx < n✝),
    ⟦assign.toAIGAssignment, { aig := (go aig rhs).val.aig, ref := (go aig rhs).val.vec.get idx hidx }⟧ =
      (eval assign rhs).getLsbD idx
aig : AIG BVBit
idx : Nat
hidx : idx < m✝
idx✝ : Nat
hidx✝ : idx✝ < m✝
⊢ ⟦assign.toAIGAssignment,
      { aig := (go (go aig lhs).1.aig rhs).1.aig, ref := ((go aig lhs).1.vec.cast ⋯).get idx✝ hidx✝ }⟧ =
    (eval assign lhs).getLsbD idx✝

Tactic:
rw [go_denote_mem_prefix]

Result:
case shiftRight.hleft
w : Nat
assign : Assignment
m✝ n✝ : Nat
lhs : BVExpr m✝
rhs : BVExpr n✝
lih :
  ∀ (aig : AIG BVBit) (idx : Nat) (hidx : idx < m✝),
    ⟦assign.toAIGAssignment, { aig := (go aig lhs).val.aig, ref := (go aig lhs).val.vec.get idx hidx }⟧ =
      (eval assign lhs).getLsbD idx
rih :
  ∀ (aig : AIG BVBit) (idx : Nat) (hidx : idx < n✝),
    ⟦assign.toAIGAssignment, { aig := (go aig rhs).val.aig, ref := (go aig rhs).val.vec.get idx hidx }⟧ =
      (eval assign rhs).getLsbD idx
aig : AIG BVBit
idx : Nat
hidx : idx < m✝
idx✝ : Nat
hidx✝ : idx✝ < m✝
⊢ ⟦assign.toAIGAssignment,
      { aig := (go aig lhs).1.aig,
        ref := { gate := (((go aig lhs).1.vec.cast ⋯).get idx✝ hidx✝).gate, hgate := ?shiftRight.hleft.hstart } }⟧ =
    (eval assign lhs).getLsbD idx✝

case shiftRight.hleft.hstart
w : Nat
assign : Assignment
m✝ n✝ : Nat
lhs : BVExpr m✝
rhs : BVExpr n✝
lih :
  ∀ (aig : AIG BVBit) (idx : Nat) (hidx : idx < m✝),
    ⟦assign.toAIGAssignment, { aig := (go aig lhs).val.aig, ref := (go aig lhs).val.vec.get idx hidx }⟧ =
      (eval assign lhs).getLsbD idx
rih :
  ∀ (aig : AIG BVBit) (idx : Nat) (hidx : idx < n✝),
    ⟦assign.toAIGAssignment, { aig := (go aig rhs).val.aig, ref := (go aig rhs).val.vec.get idx hidx }⟧ =
      (eval assign rhs).getLsbD idx
aig : AIG BVBit
idx : Nat
hidx : idx < m✝
idx✝ : Nat
hidx✝ : idx✝ < m✝
⊢ (((go aig lhs).1.vec.cast ⋯).get idx✝ hidx✝).gate < (go aig lhs).1.aig.decls.size

Proof state:
w : Nat
aig : AIG BVBit
expr : BVExpr w
assign : Assignment
⊢ ∀ (idx : Nat) (hidx : idx < w),
    ⟦assign.toAIGAssignment, { aig := (go aig expr).val.aig, ref := (go aig expr).val.vec.get idx hidx }⟧ =
      (eval assign expr).getLsbD idx

Tactic:
intro idx hidx

Result:
w : Nat
aig : AIG BVBit
expr : BVExpr w
assign : Assignment
idx : Nat
hidx : idx < w
⊢ ⟦assign.toAIGAssignment, { aig := (go aig expr).val.aig, ref := (go aig expr).val.vec.get idx hidx }⟧ =
    (eval assign expr).getLsbD idx

Proof state:
case bin.mul.hleft
w : Nat
assign : Assignment
w✝ : Nat
lhs rhs : BVExpr w✝
lih :
  ∀ (aig : AIG BVBit) (idx : Nat) (hidx : idx < w✝),
    ⟦assign.toAIGAssignment, { aig := (go aig lhs).val.aig, ref := (go aig lhs).val.vec.get idx hidx }⟧ =
      (eval assign lhs).getLsbD idx
rih :
  ∀ (aig : AIG BVBit) (idx : Nat) (hidx : idx < w✝),
    ⟦assign.toAIGAssignment, { aig := (go aig rhs).val.aig, ref := (go aig rhs).val.vec.get idx hidx }⟧ =
      (eval assign rhs).getLsbD idx
aig : AIG BVBit
idx : Nat
hidx : idx < w✝
idx✝ : Nat
hidx✝ : idx✝ < w✝
⊢ ⟦assign.toAIGAssignment,
      { aig := (go (go aig lhs).1.aig rhs).1.aig,
        ref := { lhs := (go aig lhs).1.vec.cast ⋯, rhs := (go (go aig lhs).1.aig rhs).1.vec }.lhs.get idx✝ hidx✝ }⟧ =
    (eval assign lhs).getLsbD idx✝

Tactic:
dsimp only

Result:
case bin.mul.hleft
w : Nat
assign : Assignment
w✝ : Nat
lhs rhs : BVExpr w✝
lih :
  ∀ (aig : AIG BVBit) (idx : Nat) (hidx : idx < w✝),
    ⟦assign.toAIGAssignment, { aig := (go aig lhs).val.aig, ref := (go aig lhs).val.vec.get idx hidx }⟧ =
      (eval assign lhs).getLsbD idx
rih :
  ∀ (aig : AIG BVBit) (idx : Nat) (hidx : idx < w✝),
    ⟦assign.toAIGAssignment, { aig := (go aig rhs).val.aig, ref := (go aig rhs).val.vec.get idx hidx }⟧ =
      (eval assign rhs).getLsbD idx
aig : AIG BVBit
idx : Nat
hidx : idx < w✝
idx✝ : Nat
hidx✝ : idx✝ < w✝
⊢ ⟦assign.toAIGAssignment,
      { aig := (go (go aig lhs).1.aig rhs).1.aig, ref := ((go aig lhs).1.vec.cast ⋯).get idx✝ hidx✝ }⟧ =
    (eval assign lhs).getLsbD idx✝

Proof state:
case signExtend
w : Nat
assign : Assignment
originalWidth v : Nat
inner : BVExpr originalWidth
ih :
  ∀ (aig : AIG BVBit) (idx : Nat) (hidx : idx < originalWidth),
    ⟦assign.toAIGAssignment, { aig := (go aig inner).val.aig, ref := (go aig inner).val.vec.get idx hidx }⟧ =
      (eval assign inner).getLsbD idx
aig : AIG BVBit
idx : Nat
hidx : idx < v
res : RefVecEntry BVBit v
hgo :
  (match go aig inner with
      | ⟨{ aig := aig_1, vec := evec }, haig⟩ =>
        let res := blastSignExtend aig_1 { w := originalWidth, vec := evec };
        let_fun this := ⋯;
        ⟨res, this⟩).val =
    res
⊢ ⟦assign.toAIGAssignment, { aig := res.aig, ref := res.vec.get idx hidx }⟧ =
    (eval assign (signExtend v inner)).getLsbD idx

Tactic:
dsimp only at hgo

Result:
case signExtend
w : Nat
assign : Assignment
originalWidth v : Nat
inner : BVExpr originalWidth
ih :
  ∀ (aig : AIG BVBit) (idx : Nat) (hidx : idx < originalWidth),
    ⟦assign.toAIGAssignment, { aig := (go aig inner).val.aig, ref := (go aig inner).val.vec.get idx hidx }⟧ =
      (eval assign inner).getLsbD idx
aig : AIG BVBit
idx : Nat
hidx : idx < v
res : RefVecEntry BVBit v
hgo : blastSignExtend (go aig inner).1.aig { w := originalWidth, vec := (go aig inner).1.vec } = res
⊢ ⟦assign.toAIGAssignment, { aig := res.aig, ref := res.vec.get idx hidx }⟧ =
    (eval assign (signExtend v inner)).getLsbD idx