type t = And of t * t | Or of t * t | Litt of int * bool | Top | Bot type af = Af_Prog of int * t | Af_Atom of string val neg : t -> t val xor : bool -> t -> t val replace : int -> t -> t -> t val simplify : t -> t val print : t -> unit val af_print : af -> unit val get_min_var : t -> int