+let rec infer_form sq sqf sqn f = match expr f with
+ | False -> false
+ | True -> true
+ | And(f1,f2) -> infer_form sq sqf sqn f1 && infer_form sq sqf sqn f2
+ | Or(f1,f2) -> infer_form sq sqf sqn f1 || infer_form sq sqf sqn f2
+ | Atom(dir, b, s) ->
+ let setq, setr = match dir with
+ | `Left -> sqf | `Right -> sqn | `Self -> sq in
+ (* WG: WE SUPPOSE THAT Q^r and Q^q are disjoint ! *)
+ let mem = StateSet.mem s setq || StateSet.mem s setr in
+ if b then mem else not mem
+(* End *)
+