def off.take_app_add

bend-osdev-bytes@0.1.1.0 · PROOF.bend:840

import Base
import bend-osdev-bytes@0.1.1.0/bytes.bend as B

840def off.take_app_add(xs: List<&2, B.OctByte>, +n: Nat, +ys: List<&2, B.OctByte>) -> {B.w8s.take(Nat.add(List.length(&2, B.OctByte, xs), n), List.append(&2, B.OctByte, xs, ys)) == List.append(&2, B.OctByte, xs, B.w8s.take(n, ys)) : List<&2, B.OctByte>}:
841  match xs:
842    case Nil{}:
843      {==}
844    case Con{h, t}:
845      Equal.cong(List<&2, B.OctByte>, List<&2, B.OctByte>, l => Con{h, l}, B.w8s.take(Nat.add(List.length(&2, B.OctByte, t), n), List.append(&2, B.OctByte, t, ys)), List.append(&2, B.OctByte, t, B.w8s.take(n, ys)), off.take_app_add(t, n, ys))