Poly.add: def of bend-collections-laws-crypto@1.0.0.0
Import: import bend-collections-laws-crypto@1.0.0.0/spec/crypto/aes/poly.bend as Poly
Lines 8-16 of bend-collections-laws-crypto@1.0.0.0/spec/crypto/aes/poly.bend: https://jend.leeeet.dev/read.txt?path=bend-collections-laws-crypto@1.0.0.0/spec/crypto/aes/poly.bend&start_line=8&end_line=16

import Base

# Coefficient-wise sum (XOR); the longer tail is kept.
def add(a: List<&2, Bool>, b: List<&2, Bool>) -> List<&2, Bool>:
  match a b:
    case Nil{} _:
      b
    case x <> xs Nil{}:
      x <> xs
    case x <> xs y <> ys:
      Bool.xor(x, y) <> add(xs, ys)

Uses (3):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool.xor
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List