- dotted-ilist? xprocedure
True if x is a finite, non-nil-terminated ilist. That is, there exists an n >= 0 such that (icdrn x) is neither an ipair nor (). This includes non-ipair, non-() values (e.g. symbols, numbers), which are considered to be dotted ilists of length 0.
(dotted-ilist? x) = (not (proper-ilist? x))