subject-p makes more sense as (selector, element)

For future reference, I used the following code to do this automatically, plus a
few minor manual edits (e.g., swapping rcurry and curry):

(defun seek-forward (term)
(let ((p (search-forward term nil t)))
(when p
(goto-char p))))

(defun swap-args ()
(interactive)
(save-excursion
(while (seek-forward "defmethod subject-p (")
(forward-sexp)
(transpose-sexps 1)))
(save-excursion
(while (seek-forward "(subject-p")
(forward-sexp)
(transpose-sexps 1))))