-val eval_form : (StateSet.t * StateSet.t) -> t -> bool
-(** [eval_form (sf,sn) F] evaluates the formula [F] on [(sf,sn)] *)
+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)] *)