ProofBase.append_assoc: law of minebender-game@1.0.0.0
Import: import minebender-game@1.0.0.0/proof_base.bend as ProofBase
Lines 235-241 of minebender-game@1.0.0.0/proof_base.bend: https://jend.leeeet.dev/read.txt?path=minebender-game@1.0.0.0/proof_base.bend&start_line=235&end_line=241

import Base

law append_assoc:
  for -A: Data
  for +xs: List<&2, A>
  for +ys: List<&2, A>
  for +zs: List<&2, A>
  {List.append(&2, A, List.append(&2, A, xs, ys), zs)
    == List.append(&2, A, xs, List.append(&2, A, ys, zs)) : List<&2, A>}

Uses (2):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List.append