PROOF.h.absent_none: def of bend-kit-collections@0.1.4.1
Import: import bend-kit-collections@0.1.4.1/PROOF.bend as PROOF
Lines 2284-2297 of bend-kit-collections@0.1.4.1/PROOF.bend: https://jend.leeeet.dev/read.txt?path=bend-kit-collections@0.1.4.1/PROOF.bend&start_line=2284&end_line=2297

import Base
import bend-mathlib@0.7.4.0/bool.bend as MBool
import bend-kit-collections@0.1.4.1/LAWS.bend as Laws
import bend-kit-collections@0.1.4.1/hmap.bend as M

def h.absent_none(
  ~K: Data, ~V: Data, ~eq: K -> K -> Bool, xs: List<&2, M.Entry<K, V>>, +k: K,
  ab: {Laws.hmap_absent(~K, ~V, ~eq, xs, k) == True{} : Bool}
) -> {M.HMap.entries.get(~K, ~V, ~eq, xs, k) == None{} : Maybe<&2, V>}:
  match xs:
    case Nil{}:
      {==}
    case Con{M.Entry{+key, +val}, +rest}:
      +ab = ab
      %h.sb(eq(k, key), False{},
        MBool.eq_false_of_not_eq_true(eq(k, key), MBool.eq_true_of_and_left(Bool.not(eq(k, key)), Laws.hmap_absent(~K, ~V, ~eq, rest, k), ab)))
        : {h.egc(~K, ~V, ~eq, _, val, rest, k) == None{} : Maybe<&2, V>}
      h.absent_none(~K, ~V, ~eq, rest, k,
        MBool.eq_true_of_and_right(Bool.not(eq(k, key)), Laws.hmap_absent(~K, ~V, ~eq, rest, k), ab))

Uses (12):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool.not
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Maybe
  https://jend.leeeet.dev/definition.txt?path=bend-kit-collections@0.1.4.1/LAWS.bend&name=hmap_absent
  https://jend.leeeet.dev/definition.txt?path=bend-kit-collections@0.1.4.1/PROOF.bend&name=h.egc
  https://jend.leeeet.dev/definition.txt?path=bend-kit-collections@0.1.4.1/PROOF.bend&name=h.sb
  https://jend.leeeet.dev/definition.txt?path=bend-kit-collections@0.1.4.1/hmap.bend&name=Entry
  https://jend.leeeet.dev/definition.txt?path=bend-kit-collections@0.1.4.1/hmap.bend&name=HMap.entries.get
  https://jend.leeeet.dev/definition.txt?path=bend-mathlib@0.8.1.0/bool.bend&name=eq_false_of_not_eq_true
  https://jend.leeeet.dev/definition.txt?path=bend-mathlib@0.8.1.0/bool.bend&name=eq_true_of_and_left
  https://jend.leeeet.dev/definition.txt?path=bend-mathlib@0.8.1.0/bool.bend&name=eq_true_of_and_right