def internal_least_merge

bend-mathlib@0.8.1.0 · sort.bend:145

import Base
import bend-mathlib@0.8.1.0/perm.bend as MPerm

145def internal_least_merge(~A: Data, ~le: A -> A -> Bool, +lo: A, +xs: List<&2, A>, +ys: List<&2, A>, +hx: internal_least(~A, ~le, lo, xs), +hy: internal_least(~A, ~le, lo, ys)) -> internal_least(~A, ~le, lo, MPerm.merge_by(~A, ~le, xs, ys)):
146  match xs ys:
147    case Nil{} _:
148      hy
149    case +x <> +xt Nil{}:
150      hx
151    case +x <> +xt +y <> +yt:
152      internal_least_merge_pick(~A, ~le, lo, le(x, y), x, xt, y, yt, hx, hy, internal_least_merge(~A, ~le, lo, xt, y <> yt, internal_least_cons_tail(~A, ~le, lo, x, xt, hx), hy), internal_least_merge(~A, ~le, lo, x <> xt, yt, hx, internal_least_cons_tail(~A, ~le, lo, y, yt, hy)))