Consider the code at the end of this post. un-commenting f-scope reveals
the compiler error:

;;; ERROR: unbound lexical #<tree-il (lexical x #{x 190}#)>

But without it the globalified versoin f-scope2 comiles just fine
indicating an error in the compiler.

Regards
Stefan



(define-syntax-rule (<p-lambda> (c) code ...) (lambda (a b cc d c) code
...))
(define-syntax ..
  (syntax-rules ()
    ((.. (f a ...)) (f x y z a ...))
    ((.. (s ...) (f a ...))
     (f x y z a ...))))
#;
(define (f-scope f)
  (define (g f x3)
    (define (h x2 n m)
      (lambda xx (apply (f-skip n m) x2)))
    (<p-lambda> (c)
      (.. (c2) (f c))
      (let ((n N) (m M))
        (.. ((h x3 n m) c2)))))

  (lambda x (apply (g f x) x)))

(define (h x2 n m)
  (lambda xx (apply (f-skip n m) x2)))

(define (g f x3)
  (<p-lambda> (c)
    (.. (c2) (f c))
    (let ((n N) (m M))
      (.. ((h x3 n m) c2)))))

(define (f-scope2 f)
  (lambda x (apply (g f x) x)))