+val eval_form : (StateSet.t * StateSet.t * StateSet.t) -> t -> bool
+(** [eval_form (s,sf,sn) F] evaluates the formula [F] on [(s,sf,sn)] *)
+
+val infer_form : (StateSet.t * StateSet.t) -> (StateSet.t * StateSet.t) -> (StateSet.t * StateSet.t) -> t -> bool
+(** [eval_form S Sf Sn F] infers S; (S1,S2) |- F *)
+