Spec.mtv: def of bendtorch@1.3.0.0
Import: import bendtorch@1.3.0.0/spec.bend as Spec
Lines 44-50 of bendtorch@1.3.0.0/spec.bend: https://jend.leeeet.dev/read.txt?path=bendtorch@1.3.0.0/spec.bend&start_line=44&end_line=50

import Base

# Mᵀ·g: the rows weighted by g and summed (a linear layer's backward pass to its input, dx = Wᵀ·dy)
def mtv(rows: List<&2, List<&2, Nat>>, g: List<&2, Nat>) -> List<&2, Nat>:
  match rows g:
    case Con{r, rt} Con{gi, gt}:
      vadd(vscale(gi, r), mtv(rt, gt))
    case _ _:
      Nil{}

Uses (4):
  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/spec.bend&name=vadd
  https://jend.leeeet.dev/definition.txt?path=bendtorch@1.3.0.0/spec.bend&name=vscale