let cat = ../Category/Cat/semigroupal

let vObject = Type

let Set =
      ../Category/Monoidal/Cartesian/extractCategory
        cat
        vObject
        Type
        ../Category/Set/monoidal/cartesian

in    { unit = λ(a : Type) → λ(x : a) → [ x ]
      , product =
          λ(a : Type) →
          λ(mma : List (List a)) →
            List/fold
              (List a)
              mma
              (List a)
              (λ(x : List a) → λ(y : List a) → x # y)
              ([] : List a)
      }
    : ../Monad/Type Type Set List