Common.memn: def of bend-collections-laws-crypto@1.0.0.0
Import: import bend-collections-laws-crypto@1.0.0.0/spec/lib/common.bend as Common
Lines 172-178 of bend-collections-laws-crypto@1.0.0.0/spec/lib/common.bend: https://jend.leeeet.dev/read.txt?path=bend-collections-laws-crypto@1.0.0.0/spec/lib/common.bend&start_line=172&end_line=178

import Base

# membership of a natural number in a list of them
def memn(+s: Nat, xs: List<&2, Nat>) -> Bool:
  match xs:
    case Nil{}:
      False{}
    case Con{+x, t}:
      Bool.or(Nat.is_eq(x, s), memn(s, t))

Uses (5):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool.or
  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=Base/base.bend&name=Nat.is_eq