BendMlAutograd.nbwd: def of bend-ml-autograd@0.1.1.0
Import: import bend-ml-autograd@0.1.1.0/main.bend as BendMlAutograd
Lines 53-65 of bend-ml-autograd@0.1.1.0/main.bend: https://jend.leeeet.dev/read.txt?path=bend-ml-autograd@0.1.1.0/main.bend&start_line=53&end_line=65

import Base

# REVERSE-mode derivative: g is the gradient arriving from the output; each node passes on
# g (sum) or g * value-of-the-other-factor (product) to its children and adds up what
# arrives at NX.
def nbwd(e: NE, +x: Nat, +g: Nat) -> Nat:
  match e:
    case NCst{n}:
      0n
    case NX{}:
      g
    case NAdd{a, b}:
      Nat.add(nbwd(a, x, g), nbwd(b, x, g))
    case NMul{+a, +b}:
      Nat.add(nbwd(a, x, Nat.mul(g, nval(b, x))), nbwd(b, x, Nat.mul(g, nval(a, x))))

Uses (5):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat.add
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat.mul
  https://jend.leeeet.dev/definition.txt?path=bend-ml-autograd@0.1.1.0/main.bend&name=NE
  https://jend.leeeet.dev/definition.txt?path=bend-ml-autograd@0.1.1.0/main.bend&name=nval