>>>see message#1416401 for a simple way in vfp
>>
>>This message points to the original question - which message did you mean?
>message#1416405

As I said, it doesn't solve the problem we want to solve - we only want to return non-matching values. BTW, my solution was identical to yours (I used inner join), but it doesn't achieve our goal.

	create cursor Schnaps ;
	(	c1	c(1), ;
		c2	c(1),; 
		c3	c(1) ;
	)
	
	insert into Schnaps values ('A', 'a', '1')
	insert into Schnaps values ('A', 'b', '2')
	insert into Schnaps values ('A', 'b', '3')
	insert into Schnaps values ('B', 'c', '4')
	insert into Schnaps values ('B', 'c', '4')
	insert into Schnaps values ('B', 'd', '4') && Need to return this - no match
	insert into Schnaps values ('B', 'e', '4') && added
	insert into Schnaps values ('B', 'e', '4') && added
	insert into Schnaps values ('B', 'f', '4') && added  && Need to return this - no match
	insert into Schnaps values ('A', 'b', '3')
	
*!*		select T.* from Schnaps T INNER JOIN ;
*!*		(SELECT c3, MIN(c1) as c1_min,MAX(c1) as c1_max, ;
*!*		MIN(c2) as c2_min, MAX(c2) as c2_max FROM Schnaps X group by 1 ;
*!*		HAVING COUNT(distinct(c1+c2)) > 1) X ON T.c3= X.c3 
	
	select S.* ;
		from Schnaps S, ;
			( ;
				select c3 ;
					from Schnaps ;
					group by  1 ;
					having ( count( distinct c1 + c2 ) > 1) ;
			) AA ;
			where	( S.c3 == AA.c3 )