;;; This can be a bit more optimized.
(defun perm-fixpoints (perm &optional (n (perm-size perm)))
"Return a list of the fixed points in PERM less than or equal to N,
- which is the perm's size by default.
+ which is the perm's size by default."
(check-type n (integer 1))
(loop :for i :from 1 :to n
:when (= i (perm-eval* perm i))