ProofWalk.and4_intro: law of minebender-game@1.0.0.0
Import: import minebender-game@1.0.0.0/proof_walk.bend as ProofWalk
Lines 59-68 of minebender-game@1.0.0.0/proof_walk.bend: https://jend.leeeet.dev/read.txt?path=minebender-game@1.0.0.0/proof_walk.bend&start_line=59&end_line=68

import Base

law and4_intro:
  for +a: Bool
  for +b: Bool
  for +c: Bool
  for +d: Bool
  for ea: {a == True{} : Bool}
  for eb: {b == True{} : Bool}
  for ec: {c == True{} : Bool}
  for ed: {d == True{} : Bool}
  {Bool.and(Bool.and(Bool.and(a, b), c), d) == True{} : Bool}

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=Base/base.bend&name=Equal.sym