EXPORT M2.

BASE    Day.
CONSTRUCTOR  List/1.

CONSTANT   Nil: List(Day);
   Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, Sunday : Day.

FUNCTION Cons : Day * List(Day) -> List(Day).

PREDICATE Append : List(Day) * List(Day) * List(Day);
Append3 : List(Day) *  List(Day) * List(Day) * List(Day).