TensorChainPROOF.unset_step: def of bendtorch-core@0.1.0.0
Import: import bendtorch-core@0.1.0.0/src/autograd/tensor_chain_PROOF.bend as TensorChainPROOF
Lines 321-349 of bendtorch-core@0.1.0.0/src/autograd/tensor_chain_PROOF.bend: https://jend.leeeet.dev/read.txt?path=bendtorch-core@0.1.0.0/src/autograd/tensor_chain_PROOF.bend&start_line=321&end_line=349

import Base
import bendtorch-core@0.1.0.0/src/shape/core.bend as Shape
import bendtorch-core@0.1.0.0/src/tensor/core.bend as Core
import bendtorch-core@0.1.0.0/src/autograd/gradient.bend as Gradient
import bendtorch-core@0.1.0.0/src/autograd/tensor_backward.bend as Backward
import bendtorch-core@0.1.0.0/src/autograd/tensor_chain_LAWS.bend as Laws

def unset_step(+node: Backward.Node, +shape: Shape.Shape, -value: Core.Dynamic, -saved: Backward.Saved, -slot: Gradient.Slot,
  -rest: List<&1, Backward.Entry>, -more: List<&1, Gradient.Slot>, +below: Nat, -slots: List<&1, Gradient.Slot>, -log: Laws.Log(),
  -w: Gradient.Slot, -older: List<&1, Gradient.Slot>, -left: Laws.Log(),
  at: {slots == w <> older : List<&1, Gradient.Slot>}, took: {Laws.take(log, below, w) == (Done{Gradient.Unset{}}, left) : Laws.Taken()},
  out: Run<rest, more, below, older, left>) ->
  Run<Backward.Entry{node, shape, value, saved, slot} <> rest, Gradient.Unset{} <> more, 1n+below, slots, log>:
  match out:
    case Kept{done, gradients, swept, pulled}:
      Kept{Backward.Entry{node, shape, value, saved, slot} <> done, Gradient.Unset{} <> gradients,
        Equal.cong(Backward.Swept(), Backward.Swept(),
          pair => Backward.finished(Backward.Entry{node, shape, value, saved, slot}, Gradient.Unset{}, pair),
          Backward.sweep(rest, Done{more}, below), (done, Done{gradients}), swept),
        Equal.trans(Laws.Slots(), Laws.chained(Backward.Entry{node, shape, value, saved, slot} <> rest, slots, 1n+below, log),
          Laws.chained(Backward.Entry{node, shape, value, saved, slot} <> rest, w <> older, 1n+below, log),
          Done{Gradient.Unset{} <> gradients},
          Equal.cong(List<&1, Gradient.Slot>, Laws.Slots(),
            list => Laws.chained(Backward.Entry{node, shape, value, saved, slot} <> rest, list, 1n+below, log), slots, w <> older, at),
          Equal.trans(Laws.Slots(), Laws.reached(node, saved, Laws.take(log, below, w), next => Laws.chained(rest, older, below, next)),
            Laws.reached(node, saved, (Done{Gradient.Unset{}}, left), next => Laws.chained(rest, older, below, next)),
            Done{Gradient.Unset{} <> gradients},
            Equal.cong(Laws.Taken(), Laws.Slots(), taken => Laws.reached(node, saved, taken, next => Laws.chained(rest, older, below, next)),
              Laws.take(log, below, w), (Done{Gradient.Unset{}}, left), took),
            Equal.cong(Laws.Slots(), Laws.Slots(), result => Backward.prepend(Gradient.Slot, Gradient.Unset{}, result),
              Laws.chained(rest, older, below, left), Done{gradients}, pulled)))}
    case Stopped{done, error, swept}:
      Stopped{Backward.Entry{node, shape, value, saved, slot} <> done, error,
        Equal.cong(Backward.Swept(), Backward.Swept(),
          pair => Backward.finished(Backward.Entry{node, shape, value, saved, slot}, Gradient.Unset{}, pair),
          Backward.sweep(rest, Done{more}, below), (done, Fail{error}), swept)}

Uses (23):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Equal.cong
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Equal.trans
  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=Result
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Sigma
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/autograd/gradient.bend&name=Slot
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/autograd/tensor_backward.bend&name=Entry
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/autograd/tensor_backward.bend&name=Node
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/autograd/tensor_backward.bend&name=Saved
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/autograd/tensor_backward.bend&name=Swept
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/autograd/tensor_backward.bend&name=finished
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/autograd/tensor_backward.bend&name=prepend
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/autograd/tensor_backward.bend&name=sweep
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/autograd/tensor_chain_LAWS.bend&name=Log
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/autograd/tensor_chain_LAWS.bend&name=Slots
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/autograd/tensor_chain_LAWS.bend&name=Taken
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/autograd/tensor_chain_LAWS.bend&name=chained
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/autograd/tensor_chain_LAWS.bend&name=reached
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/autograd/tensor_chain_LAWS.bend&name=take
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/autograd/tensor_chain_PROOF.bend&name=Run
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/shape/core.bend&name=Shape
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/tensor/core.bend&name=Dynamic