Minimum member in a list of naturals.
(min-nats x) → *
Typically you would only use this on non-empty lists, but as a
reasonable default we say the minimum of the empty list is
(defun min-nats (x) (declare (xargs :guard (nat-listp x))) (let ((__function__ 'min-nats)) (declare (ignorable __function__)) (cond ((atom x) 0) ((atom (cdr x)) (lnfix (car x))) (t (min (lnfix (car x)) (min-nats (cdr x)))))))