def append_nil

bend-collections-laws-math@1.0.0.0 · proofs/lib/list.bend:11

import Base
import bend-collections-laws-math@1.0.0.0/spec/lib/common.bend as SC

11def append_nil(-A: Data, +xs: List<&2, A>) -> {SC.append(A, xs, Nil{}) == xs : List<&2, A>}:
12  match xs:
13    case Nil{}:
14      {==}
15    case Con{+h, +t}:
16      cons_cong(A, h, SC.append(A, t, Nil{}), t, append_nil(A, t))