how emanate 'two-sided' unparalleled index twin fields?

how i good emanate unparalleled index twin fields list this:
create list t (a integer, b integer);

where any unparalleled multiple twin opposite numbers can't seem some-more once same quarrel table.

in method difference quarrel exists such a=1 b=2, another quarrel can't exist where a=2 b=1 a=1 b=2. difference twin numbers can't seem together some-more once any order.

i have thought such imprisonment called, hence 'two-sided unparalleled index' name title.

update: i have multiple pivotal columns (a,b), quarrel (1,2) exists database, illusory insert another quarrel (2,1) but an error. i'm looking proceed hinder same camber numbers being used some-more once in any order...