M'.Boolean
type boolean = L.boolean
val not : (boolean, boolean) Monadic_Arity.ar1
val (&&) : (boolean, boolean, boolean) Monadic_Arity.ar2
val (||) : (boolean, boolean, boolean) Monadic_Arity.ar2
val true_ : boolean Monadic_Arity.ar0
val false_ : boolean Monadic_Arity.ar0