Backward.find: def of bendtorch-core@0.1.0.0
Import: import bendtorch-core@0.1.0.0/src/autograd/backward.bend as Backward
Lines 67-76 of bendtorch-core@0.1.0.0/src/autograd/backward.bend: https://jend.leeeet.dev/read.txt?path=bendtorch-core@0.1.0.0/src/autograd/backward.bend&start_line=67&end_line=76

import Base

# The element with id `id` in a newest-first list of count elements: the head
# has id count - 1, and the walk counts down from it.
def find(-A: Data, xs: List<&2, A>, +count: Nat, +id: Nat) -> Maybe<&2, A>:
  match xs count:
    case Nil{} count:
      None{}
    case Con{head, rest} 0n:
      None{}
    case Con{head, +rest} 1n+below:
      picked(A, head, unit => find(A, rest, below, id), Nat.is_eq(below, id))

Uses (5):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Maybe
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat.is_eq
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/autograd/backward.bend&name=picked