Tensor.permute_bwd: def of bendtorch@1.3.0.0
Import: import bendtorch@1.3.0.0/tensor.bend as Tensor
Lines 512-516 of bendtorch@1.3.0.0/tensor.bend: https://jend.leeeet.dev/read.txt?path=bendtorch@1.3.0.0/tensor.bend&start_line=512&end_line=516

import Base

# the gradient of permute: dy put back where each number came from
def permute_bwd(+s: List<&2, Nat>, +p: List<&2, Nat>, dy: Tensor<permuted(s, p)>) -> TP<permuted(s, p), s>:
  match dy:
    case Tensor{d}:
      tp_of(permuted(s, p), s, place_l(numel(s), 0, perm_map(s, p), Array.get(F32, d, 0), new(numel(s))))

Uses (12):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Array.get
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=F32
  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@1.3.0.0/tensor.bend&name=TP
  https://jend.leeeet.dev/definition.txt?path=bendtorch@1.3.0.0/tensor.bend&name=Tensor
  https://jend.leeeet.dev/definition.txt?path=bendtorch@1.3.0.0/tensor.bend&name=new
  https://jend.leeeet.dev/definition.txt?path=bendtorch@1.3.0.0/tensor.bend&name=numel
  https://jend.leeeet.dev/definition.txt?path=bendtorch@1.3.0.0/tensor.bend&name=perm_map
  https://jend.leeeet.dev/definition.txt?path=bendtorch@1.3.0.0/tensor.bend&name=permuted
  https://jend.leeeet.dev/definition.txt?path=bendtorch@1.3.0.0/tensor.bend&name=place_l
  https://jend.leeeet.dev/definition.txt?path=bendtorch@1.3.0.0/tensor.bend&name=tp_of