-- 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.inr
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
hlt : 0 < originalWidth
⊢ (if hidx : idx < { w := originalWidth, vec := (go aig inner).1.vec }.w then
      ⟦assign.toAIGAssignment,
        { aig := (go aig inner).1.aig, ref := { w := originalWidth, vec := (go aig inner).1.vec }.vec.get idx hidx }⟧
    else
      ⟦assign.toAIGAssignment,
        { aig := (go aig inner).1.aig,
          ref :=
            { w := originalWidth, vec := (go aig inner).1.vec }.vec.get
              ({ w := originalWidth, vec := (go aig inner).1.vec }.w - 1) ⋯ }⟧) =
    (eval assign (signExtend v inner)).getLsbD idx

case signExtend.inr.htarget
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
hlt : 0 < originalWidth
⊢ 0 < { w := originalWidth, vec := (go aig inner).1.vec }.w

Tactic:
simp only [eval_signExtend]

Result:
case signExtend.inr
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
hlt : 0 < originalWidth
⊢ (if h : idx < originalWidth then
      ⟦assign.toAIGAssignment, { aig := (go aig inner).1.aig, ref := (go aig inner).1.vec.get idx ⋯ }⟧
    else
      ⟦assign.toAIGAssignment,
        { aig := (go aig inner).1.aig, ref := (go aig inner).1.vec.get (originalWidth - 1) ⋯ }⟧) =
    (BitVec.signExtend v (eval assign inner)).getLsbD idx

case signExtend.inr.htarget
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
hlt : 0 < originalWidth
⊢ 0 < { w := originalWidth, vec := (go aig inner).1.vec }.w

Proof state:
case bin.umod.hleft.hidx
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✝
⊢ idx✝ < w✝

Tactic:
assumption

Result:
no goals

Proof state:
case bin.umod.hright
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 }.rhs.get idx✝ hidx✝ }⟧ =
    (eval assign rhs).getLsbD idx✝

Tactic:
rw [← rih]

Result:
no goals

Proof state:
case bin.umod.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.umod.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✝