impc:ti:binary-arity   scheme

;; replace (* 2 3 4 5) or (+ 2 3 4 5)
;; with (* 2 (* 3 (* 4 5))) etc..
(define impc:ti:binary-arity
  (lambda (ast inbody?)
    (let ((op (car ast))
          (inlst (reverse (cdr ast))))
      (let loop ((rest (cdr inlst))
                 (lst (car inlst)))
        (if (null? rest) lst
            (loop (cdr rest) (cons op (cons (impc:ti:first-transform (car rest) inbody?) (list lst)))))))))