PROOF.c4.d: def of bend-kit-collections@0.1.4.1
Import: import bend-kit-collections@0.1.4.1/PROOF.bend as PROOF
Lines 104-108 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=104&end_line=108

import Base
import bend-mathlib@0.7.4.0/bool.bend as MBool

def c4.d(
  +a: Bool, +b: Bool, +c: Bool, +d: Bool,
  e: {Bool.and(Bool.and(Bool.and(a, b), c), d) == True{} : Bool}
) -> {d == True{} : Bool}:
  MBool.eq_true_of_and_right(Bool.and(Bool.and(a, b), c), d, e)

Uses (3):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool.and
  https://jend.leeeet.dev/definition.txt?path=bend-mathlib@0.8.1.0/bool.bend&name=eq_true_of_and_right