[rules-users] operator choices in GUVNOR for decision tables

Using Drools 5 I'm using a decision table in Guvnor and want to see if a value is in an array or list, but I don't see list or collection operators available, such as 'in', or 'contains.' How do I see if '5' is in [5,10,15,20] without writing a function or otherwise writing something custom? What am I missing? Is there a way to variablize an array without passing in a class? Thanks, Robert Costello