(define (make rcs targets . maybe-arg)
  (let-optionals maybe-arg ((init-state (list)))
    (let* ((rules (rcs->rules rcs))
	   (rule-set (rules->rule-set rules))
	   (target-rules (map (lambda (t) (lookup-rule t rules))
			      targets)))
      (map (lambda (t) 
	     (rule-make t init-state rule-set))
	   target-rules))))