- dotted-list? xprocedure
True if X is a finite, non-nil-terminated list. That is, there exists an N >= 0 such that cdr^N(X) is neither a pair nor (). This includes non-pair, non-() values (e.g. symbols, numbers), which are considered to be dotted lists of length 0.
(not (dotted-list? X)) = (or (proper-list? X) (circular-list? X))