MIMWAL . Check if a string is part of a set of strings

Hi,

I need to validate if a string attribute corresponds to any of the 10 allowed ones

What operations/operators do I have available for this in MIMWAL? 

I just found a referente to several types of functions (including text functions), but I do not see whow can I have in MIMWAL this kind of simple constructs. Any help?

Thanks,

JD