SlicePROOF.target_split: def of bendtorch-core@0.1.0.0
Import: import bendtorch-core@0.1.0.0/src/tensor/slice_PROOF.bend as SlicePROOF
Lines 809-824 of bendtorch-core@0.1.0.0/src/tensor/slice_PROOF.bend: https://jend.leeeet.dev/read.txt?path=bendtorch-core@0.1.0.0/src/tensor/slice_PROOF.bend&start_line=809&end_line=824

import Base
import bendtorch-core@0.1.0.0/src/tensor/slice.bend as Slice
import bendtorch-core@0.1.0.0/src/tensor/slice_LAWS.bend as Laws
import bendtorch-core@0.1.0.0/src/tensor/batched_matmul_PROOF.bend as BatchedProof

# Position (o * extent + i) * inner + r splits into row o * extent + i and
# remainder r, and the row into o and i.
def target_split(+outer: Nat, +extent: Nat, +inner: Nat, +start: Nat, +step: Nat, +length: Nat, +o: Nat, +i: Nat, +r: Nat,
  +i_below: {Nat.is_lt(i, extent) == True{} : Bool}, +r_below: {Nat.is_lt(r, inner) == True{} : Bool}) ->
  {Slice.target(Slice.Plan{outer, extent, inner, start, step, length}, Laws.position(extent, inner, o, i, r)) ==
    picked_at(outer, extent, inner, start, step, length, Nat.add(Nat.mul(o, extent), i), r, i) : Maybe<&2, Nat>}:
  +row = Nat.add(Nat.mul(o, extent), i)
  +pos = Laws.position(extent, inner, o, i, r)
  %Equal.sym(Nat, Nat.div(pos, inner), row, BatchedProof.div_exact(row, inner, r, r_below)) :
    {target_of(outer, extent, inner, start, step, length, _, Nat.mod(pos, inner)) ==
      picked_at(outer, extent, inner, start, step, length, row, r, i) : Maybe<&2, Nat>}
  %Equal.sym(Nat, Nat.mod(pos, inner), r, BatchedProof.mod_exact(row, inner, r, r_below)) :
    {target_of(outer, extent, inner, start, step, length, row, _) == picked_at(outer, extent, inner, start, step, length, row, r, i) : Maybe<&2, Nat>}
  %Equal.sym(Nat, Nat.mod(row, extent), i, BatchedProof.mod_exact(o, extent, i, i_below)) :
    {picked_at(outer, extent, inner, start, step, length, row, r, _) == picked_at(outer, extent, inner, start, step, length, row, r, i) : Maybe<&2, Nat>}
  {==}

Uses (16):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Equal.sym
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Maybe
  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.div
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat.is_lt
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat.mod
  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/tensor/batched_matmul_PROOF.bend&name=div_exact
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/tensor/batched_matmul_PROOF.bend&name=mod_exact
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/tensor/slice.bend&name=Plan
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/tensor/slice.bend&name=target
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/tensor/slice_LAWS.bend&name=position
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/tensor/slice_PROOF.bend&name=picked_at
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/tensor/slice_PROOF.bend&name=target_of