I assume the answer is 'NO', but thought I'd check if there was a way to get the syntax to work.
I tried a case function:
field = x; result1
field = "a" or "b"; result2;
The first 2 options work but if the field should really elicit result3, I still get result2. If I don't have "a" or "b" it works. I can of course write more lines to obviate the use of or but it would have been a nice way to shorten the calc. BTW, I have tried putting ( ) around the alternatives or's, but it doesn't help.