rw [← hgo]
case isTrue
α : Type
inst✝² : BEq α
inst✝¹ : Hashable α
inst✝ : DecidableEq α
w : Nat
aig : AIG α
curr : Nat
hcurr : curr ≤ w
cin : aig.Ref
s : aig.RefStream curr
lhs rhs : aig.RefStream w
idx : Nat
hidx : idx < curr
res : RefStreamEntry α w
h✝ : curr < w
hgo :
  go (mkFullAdder aig { lhs := lhs.getRef curr h✝, rhs := rhs.getRef curr h✝, cin := cin }).aig (curr + 1) ⋯
      (mkFullAdder aig { lhs := lhs.getRef curr h✝, rhs := rhs.getRef curr h✝, cin := cin }).cout
      ((s.cast ⋯).pushRef (mkFullAdder aig { lhs := lhs.getRef curr h✝, rhs := rhs.getRef curr h✝, cin := cin }).out)
      (lhs.cast ⋯) (rhs.cast ⋯) =
    res
⊢ ∀ (hfoo : aig.decls.size ≤ res.aig.decls.size), res.stream.getRef idx ⋯ = (s.getRef idx hidx).cast hfoo
case isTrue
α : Type
inst✝² : BEq α
inst✝¹ : Hashable α
inst✝ : DecidableEq α
w : Nat
aig : AIG α
curr : Nat
hcurr : curr ≤ w
cin : aig.Ref
s : aig.RefStream curr
lhs rhs : aig.RefStream w
idx : Nat
hidx : idx < curr
res : RefStreamEntry α w
h✝ : curr < w
hgo :
  go (mkFullAdder aig { lhs := lhs.getRef curr h✝, rhs := rhs.getRef curr h✝, cin := cin }).aig (curr + 1) ⋯
      (mkFullAdder aig { lhs := lhs.getRef curr h✝, rhs := rhs.getRef curr h✝, cin := cin }).cout
      ((s.cast ⋯).pushRef (mkFullAdder aig { lhs := lhs.getRef curr h✝, rhs := rhs.getRef curr h✝, cin := cin }).out)
      (lhs.cast ⋯) (rhs.cast ⋯) =
    res
⊢ ∀
    (hfoo :
      aig.decls.size ≤
        (go (mkFullAdder aig { lhs := lhs.getRef curr h✝, rhs := rhs.getRef curr h✝, cin := cin }).aig (curr + 1) ⋯
                (mkFullAdder aig { lhs := lhs.getRef curr h✝, rhs := rhs.getRef curr h✝, cin := cin }).cout
                ((s.cast ⋯).pushRef
                  (mkFullAdder aig { lhs := lhs.getRef curr h✝, rhs := rhs.getRef curr h✝, cin := cin }).out)
                (lhs.cast ⋯) (rhs.cast ⋯)).aig.decls.size),
    (go (mkFullAdder aig { lhs := lhs.getRef curr h✝, rhs := rhs.getRef curr h✝, cin := cin }).aig (curr + 1) ⋯
              (mkFullAdder aig { lhs := lhs.getRef curr h✝, rhs := rhs.getRef curr h✝, cin := cin }).cout
              ((s.cast ⋯).pushRef
                (mkFullAdder aig { lhs := lhs.getRef curr h✝, rhs := rhs.getRef curr h✝, cin := cin }).out)
              (lhs.cast ⋯) (rhs.cast ⋯)).stream.getRef
        idx ⋯ =
      (s.getRef idx hidx).cast hfoo