rx-trans-forms
rx-trans-forms is a compiled Lisp function in `rx.el
'.
(rx-trans-forms FORM &optional SKIP)
If FORM's length is greater than two, transform it to length two.
A form (HEAD REST ...) becomes (HEAD (and REST ...)).
If SKIP is non-nil, allow that number of items after the head, i.e.
`(= N REST ...)' becomes `(= N (and REST ...))' if SKIP is 1.