law signed_narrow_first

bendtorch-core@0.1.0.0 · src/tensor/signed_LAWS.bend:371

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

371# A signed narrow takes a start in -extent..extent, PyTorch's range. A start
372# counted from the start is the unsigned narrow's, which refuses one past
373# the extent itself; Last{k} below the extent is wrapped among it ...
374law signed_narrow_first:
375  for input: Core.Dynamic
376  for +dim: Signed.Position
377  for +k: U32
378  for +length: U32
379  {Signed.narrow(input, dim, Signed.First{k}, length) == Slice.narrow(input, axis_of(input, dim), k, length) :
380    Core.Dynamic & Result<&2, &1, Slice.Error, Core.Dynamic>}