IndexProofs.flatten_unflatten: def of bendtorch-core@0.1.0.0
Import: import bendtorch-core@0.1.0.0/src/shape/index_proofs.bend as IndexProofs
Lines 123-133 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=123&end_line=133

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

def flatten_unflatten(+dims: List<&2, Nat>, +index: Shape.Fin(Shape.numel(dims))) -> {Shape.flatten(dims, Shape.unflatten(dims, index)) == index : Shape.Fin(Shape.numel(dims))}:
  match dims:
    case Nil{}:
      match index:
        case Shape.FZero{}:
          {==}
        case Shape.FNext{previous}:
          match previous:
    case +head <> +tail:
      %pack_unpack(head, Shape.numel(tail), index) : {Shape.flatten(head <> tail, Shape.unflatten(head <> tail, index)) == _ : Shape.Fin(Shape.numel(head <> tail))}
      flatten_unflatten_step(head, tail, +last => flatten_unflatten(tail, last), Shape.Fin.unpack(head, Shape.numel(tail), index))

Uses (10):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat
  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.Step
  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/core.bend&name=flatten
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/shape/core.bend&name=numel
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/shape/core.bend&name=unflatten
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/shape/index_proofs.bend&name=flatten_unflatten_step
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/shape/index_proofs.bend&name=pack_unpack