ProofSums.csum_append: law of minebender-game@1.0.0.0
Import: import minebender-game@1.0.0.0/proof_sums.bend as ProofSums
Lines 86-93 of minebender-game@1.0.0.0/proof_sums.bend: https://jend.leeeet.dev/read.txt?path=minebender-game@1.0.0.0/proof_sums.bend&start_line=86&end_line=93

import Base
import minebender-game@1.0.0.0/types.bend as T

law csum_append:
  for ~A: Data
  for ~f: A -> Nat
  for +d: A
  for +g: T.Grid(A)
  for +xs: List<&2, T.Pos>
  for +ys: List<&2, T.Pos>
  {csum(~A, ~f, d, g, List.append(&2, T.Pos, xs, ys)) == Nat.add(csum(~A, ~f, d, g, xs), csum(~A, ~f, d, g, ys)) : Nat}

Uses (10):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Equal.sym
  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
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat.add
  https://jend.leeeet.dev/definition.txt?path=minebender-game@1.0.0.0/board.bend&name=at
  https://jend.leeeet.dev/definition.txt?path=minebender-game@1.0.0.0/proof_base.bend&name=add_assoc
  https://jend.leeeet.dev/definition.txt?path=minebender-game@1.0.0.0/proof_sums.bend&name=csum
  https://jend.leeeet.dev/definition.txt?path=minebender-game@1.0.0.0/types.bend&name=Grid
  https://jend.leeeet.dev/definition.txt?path=minebender-game@1.0.0.0/types.bend&name=Pos