(define match-expander-er
  (lambda (form rename compare?)
    (let* ((pats (car (cdr form)))
           (results (cadr (cdr form)))
           (stack (caddr (cdr form)))
           (fail (cadddr (cdr form)))
           (%interpret-pat (rename 'interpret-pat))
           (p (compile-patterns pats results)))
      `(,%interpret-pat ,p
                        ,stack
                        ,fail))))