IndexProofs.pack_unpack: def of bendtorch-core@0.1.0.0
Import: import bendtorch-core@0.1.0.0/src/shape/index_proofs.bend as IndexProofs
Lines 110-116 of bendtorch-core@0.1.0.0/src/shape/index_proofs.bend: https://jend.leeeet.dev/read.txt?path=bendtorch-core@0.1.0.0/src/shape/index_proofs.bend&start_line=110&end_line=116

import Base
import bendtorch-core@0.1.0.0/src/shape/core.bend as Shape

def pack_unpack(+a: Nat, +b: Nat, +index: Shape.Fin(Nat.mul(a, b))) -> {Shape.Fin.pack(a, b, Shape.Fin.unpack(a, b, index)) == index : Shape.Fin(Nat.mul(a, b))}:
  match a:
    case 0n:
      match index:
    case 1n+p:
      %merge_split(b, Nat.mul(p, b), index) : {Shape.Fin.pack(1n+p, b, Shape.Fin.unpack(1n+p, b, index)) == _ : Shape.Fin(Nat.add(b, Nat.mul(p, b)))}
      pack_unpack_step(p, b, +index => pack_unpack(p, b, index), Shape.Fin.split(b, Nat.mul(p, b), index))

Uses (9):
  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=Base/base.bend&name=Nat.mul
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/shape/core.bend&name=Fin
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/shape/core.bend&name=Fin.pack
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/shape/core.bend&name=Fin.split
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/shape/core.bend&name=Fin.unpack
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/shape/index_proofs.bend&name=merge_split
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/shape/index_proofs.bend&name=pack_unpack_step