Proposal: upper-case?, lower-case? and title-case?

[Kazimir Majorinc]

Not a big deal, but upper-case?, lower-case? and title-case? are consistent with other predicates, and low hanging opportunity for slightly shorter and faster code. It might be that many persistent Newlispers miss these, although only occasionally. More generally, maybe some other single variable functions (like unique, sort) deserve their predicates defined as f|->(= x (f x)) .