instance ( Ord knoten, Show knoten, ShowText knoten, ToDoc knoten , ToDoc (Graph knoten), Show (Graph knoten), Read (Graph knoten) , ToDoc (Labeling knoten), Show (Labeling knoten), Read (Labeling knoten) ) => Problem Graceful (Graph knoten) (Labeling knoten) where validiere Graceful graph labeling verifiziere Graceful graph labeling getInstanz Graceful graph labeling dateiName getBeweis Graceful graph labeling dateiName