MIT 6.001                                       Fall, 1997
Instructor: A. Meyer

                 Recitation #7, Notes for Wed., 10/29/97

We reviewed Streams from the Tuesday lecture, explaining why
   (define zeroes-list (cons 0 zeroes-list))
causes an "undefined variable: ZEROES-LIST" error, but
   (define zeroes-stream (cons 0 zeroes-stream))
works fine:
   (stream-car zeroes-stream) ==> 0
   (stream-car (stream-cdr zeroes-stream)) ==> 0
        .
        .
        .

We discussed memoization and worked on the

IN-CLASS EXERCISES:

1.  Complete the definition of a memoized SQRT procedure:
     (define memoized-sqrt
        ...)

2.  Define a procedure MEMOIZE: Proc --> Proc where Proc = Num --> Value
    which "memoizes" its argument.  For example, a solution to Exercise 1
    would now also be:
    (define memoized-sqrt (memoize sqrt))

SOLUTION: See SICP, p.273.