ReduceParallelProof.masked_below: def of bendtorch-core@0.1.0.0
Import: import bendtorch-core@0.1.0.0/src/autograd/reduce_parallel_proof.bend as ReduceParallelProof
Lines 208-222 of bendtorch-core@0.1.0.0/src/autograd/reduce_parallel_proof.bend: https://jend.leeeet.dev/read.txt?path=bendtorch-core@0.1.0.0/src/autograd/reduce_parallel_proof.bend&start_line=208&end_line=222

import Base
import bendtorch-core@0.1.0.0/src/shape/core.bend as Shape
import bendtorch-core@0.1.0.0/src/tensor/contracts/broadcast_proof.bend as BroadcastProof
import bendtorch-core@0.1.0.0/src/autograd/reduce_fiber_proof.bend as Fiber

def masked_below(+plan: Shape.BroadcastPlan, +rows: List<&2, Shape.Row>,
  +exact: {rows == Shape.index_table(Shape.extents(Shape.left_shape(plan)), Shape.extents(Shape.right_shape(plan)), Shape.extents(Shape.output_shape(plan))) : List<&2, Shape.Row>},
  +target: Nat, +n: Nat, +cursor: Nat,
  +room: {Nat.is_le(Nat.add(cursor, n), Shape.logical_numel(Shape.dimensions(Shape.output_shape(plan)))) == True{} : Bool}) ->
  {all_below(Fiber.masked(n, rows, target, 0n, cursor), Shape.logical_numel(Shape.dimensions(Shape.right_shape(plan)))) == True{} : Bool}:
  match n:
    case 0n:
      {==}
    case 1n+m:
      +map : Shape.Index<Shape.extents(Shape.left_shape(plan)), Shape.extents(Shape.right_shape(plan)), Shape.extents(Shape.output_shape(plan))> =
        Shape.Indexed{rows, exact}
      kept_below(Nat.is_eq(Shape.walk_left(rows, cursor), target), Shape.walk_right(rows, cursor), Fiber.masked(m, rows, target, 0n, 1n+cursor),
        Shape.logical_numel(Shape.dimensions(Shape.right_shape(plan))),
        BroadcastProof.right_walk_bound(plan, map, cursor, Fiber.lt_of_room(cursor, m, Shape.logical_numel(Shape.dimensions(Shape.output_shape(plan))), room)),
        masked_below(plan, rows, exact, target, m, 1n+cursor, Fiber.le_step(cursor, m, Shape.logical_numel(Shape.dimensions(Shape.output_shape(plan))), room)))

Uses (24):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool
  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=Base/base.bend&name=Nat.add
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat.is_eq
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat.is_le
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/autograd/reduce_fiber_proof.bend&name=le_step
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/autograd/reduce_fiber_proof.bend&name=lt_of_room
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/autograd/reduce_fiber_proof.bend&name=masked
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/autograd/reduce_parallel_proof.bend&name=all_below
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/autograd/reduce_parallel_proof.bend&name=kept_below
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/shape/core.bend&name=BroadcastPlan
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/shape/core.bend&name=Index
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/shape/core.bend&name=Row
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/shape/core.bend&name=dimensions
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/shape/core.bend&name=extents
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/shape/core.bend&name=index_table
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/shape/core.bend&name=left_shape
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/shape/core.bend&name=logical_numel
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/shape/core.bend&name=output_shape
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/shape/core.bend&name=right_shape
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/shape/core.bend&name=walk_left
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/shape/core.bend&name=walk_right
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/tensor/contracts/broadcast_proof.bend&name=right_walk_bound