Sig.BOOLEAN_FORWARD
include BOOLEAN_BACKWARD
type boolean
module Arity : ARITY
val not : (boolean, boolean) Arity.ar1
val (&&) : (boolean, boolean, boolean) Arity.ar2
val (||) : (boolean, boolean, boolean) Arity.ar2
val true_ : boolean Arity.ar0
val false_ : boolean Arity.ar0