PR# 19881 New PREDICATE feature:converse or item_not

I would appreciate a function (suggested name: converse) in PREDICATE that returns a PREDICATE that returns the boolean inverse of the result of calling the current PREDICATE. 

Alternatively, a feature item_not in PREDICATE that returns a boolean not of item.

I think one or the other could reduce the need for inline agents in some situations and might also improve run-time efficiency for such calls

Thanks 
Martin