contradiction
α : Type u_1
as bs : Array α
start stop i : Nat
hstart : start ≤ stop
hstop : stop ≤ bs.size
hi : i < 0
ha : as.size + i < (foldl push as bs start stop).size
hb : start + i < bs.size
heq : start = stop
⊢ (foldl push as bs start stop)[as.size + i] = bs[start + i]
no goals