Compound predicates? Not working!?

If you mouse over the part of the dialogue box where you select rules for smart groups, it claims that if you press option-click on the ±sign, you can set up compound predicates. I gather this means you could tell it to find “A and (B or C)”, or in other words “ALL of A and (ANY of B or C).” I have never been able to detect any evidence that this feature has in fact been implemented. Am I wrong?

That’s a default tooltip of Leopard, compound predicates are not yet supported.

However, you can just enter “A AND (B OR C)” (assuming you’re searching for text) as smart groups support boolean/proximity operators, phrases, parenthesis and wildcards just like the search.