intros
case hprefix.idx_eq
w : Nat
aig : AIG BVBit
expr : BVExpr w
assign : Assignment
start : Nat
hstart : start < aig.decls.size
⊢ ∀ (idx : Nat) (h : idx < { aig := aig, ref := { gate := start, hgate := hstart } }.aig.decls.size),
    (go aig expr).val.aig.decls[idx] = { aig := aig, ref := { gate := start, hgate := hstart } }.aig.decls[idx]
case hprefix.idx_eq
w : Nat
aig : AIG BVBit
expr : BVExpr w
assign : Assignment
start : Nat
hstart : start < aig.decls.size
idx✝ : Nat
h✝ : idx✝ < { aig := aig, ref := { gate := start, hgate := hstart } }.aig.decls.size
⊢ (go aig expr).val.aig.decls[idx✝] = { aig := aig, ref := { gate := start, hgate := hstart } }.aig.decls[idx✝]