scheme :: CIRCCMB3:sch 6
1AryDef{ F1() -> non empty set , F2( object ) -> Element of F1() } :
( ex f being Function of (1 -tuples_on F1()),F1() st
for x being Element of F1() holds f . <*x*> = F2(x) & ( for f1, f2 being Function of (1 -tuples_on F1()),F1() st ( for x being Element of F1() holds f1 . <*x*> = F2(x) ) & ( for x being Element of F1() holds f2 . <*x*> = F2(x) ) holds
f1 = f2 ) )