Alternative strategy for scanning out definitions

Consider an alternative strategy for scanning out definitions that translates the example in the text to

(lambda <vars>
  (let ((u '*unassigned*)
        (v '*unassigned*))
    (let ((a <e1>)
          (b <e2>))
      (set! u a)
      (set! v b))
    <e3>))

Here a and b are meant to represent new variable names, created by the interpreter, that do not appear in the user's program. Consider the solve procedure from section 3.5.4:

(define (solve f y0 dt)
  (define y (integral (delay dy) y0 dt))
  (define dy (stream-map f y))
  y)

Will this procedure work if internal definitions are scanned out as shown in this exercise? What if they are scanned out as shown in the text? Explain.

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