+type providers = {provideC : string SM.map,
+ provideT : string SM.map,
+ provideV : string SM.map}
+
+fun providesContext (p : providers, s) = SM.find (#provideC p, s)
+fun providesType (p : providers, s) = SM.find (#provideT p, s)
+fun providesValue (p : providers, s) = SM.find (#provideV p, s)
+