Functional letrec

Here is my try:

(define-macro (my-letrec bindings . expr-list)
  (define (gen-sym-list n acc)
    (if (zero? n)
        acc
        (gen-sym-list (- n 1) (cons (gensym) acc))))

  (if (not (list? bindings))
      (error "Bad bindings: " bindings))
  (let* ((num-bindings (length bindings))
         (proc-sym-list (gen-sym-list num-bindings '()))
         (var-list (map (lambda (var-bind) (car var-bind)) bindings))
         (z-list
          (map
           (lambda (proc-sym)
             `(lambda arg (apply (,proc-sym ,@[EMAIL PROTECTED]
) arg)))
           proc-sym-list))
         (y-list
          (map
           (lambda (var-bind)
             (let ((var (car var-bind)) (bind (cadr var-bind)))
               `(lambda ,proc-sym-list
                  ((lambda ,var-list ,bind)
                   ,@[EMAIL PROTECTED]
))))
           bindings))
         (y-sym-list (gen-sym-list num-bindings '())))
    `(let ,(map
            (lambda (y-sym y)
              `(,y-sym ,y))
            y-sym-list y-list)
       (let ,(map
              (lambda (var y-sym)
                `(,var (,y-sym ,@[EMAIL PROTECTED]
)))
              var-list y-sym-list)
         ,@[EMAIL PROTECTED]
))))