SignedLAWS.signed_narrow_first: law of bendtorch-core@0.1.0.0
Import: import bendtorch-core@0.1.0.0/src/tensor/signed_LAWS.bend as SignedLAWS
Lines 371-380 of bendtorch-core@0.1.0.0/src/tensor/signed_LAWS.bend: https://jend.leeeet.dev/read.txt?path=bendtorch-core@0.1.0.0/src/tensor/signed_LAWS.bend&start_line=371&end_line=380

import Base
import bendtorch-core@0.1.0.0/src/tensor/core.bend as Core
import bendtorch-core@0.1.0.0/src/tensor/signed.bend as Signed
import bendtorch-core@0.1.0.0/src/tensor/slice.bend as Slice

# A signed narrow takes a start in -extent..extent, PyTorch's range. A start
# counted from the start is the unsigned narrow's, which refuses one past
# the extent itself; Last{k} below the extent is wrapped among it ...
law signed_narrow_first:
  for input: Core.Dynamic
  for +dim: Signed.Position
  for +k: U32
  for +length: U32
  {Signed.narrow(input, dim, Signed.First{k}, length) == Slice.narrow(input, axis_of(input, dim), k, length) :
    Core.Dynamic & Result<&2, &1, Slice.Error, Core.Dynamic>}

Uses (9):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Pair
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Result
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/tensor/core.bend&name=Dynamic
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/tensor/signed.bend&name=Position
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/tensor/signed.bend&name=narrow
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/tensor/signed_LAWS.bend&name=axis_of
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/tensor/slice.bend&name=Error
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/tensor/slice.bend&name=narrow