sanity check: <=, >=

[gls@Think.COM]

   Date: 06 Jul 88 11:29:02 PDT (Wed)
   From: willc@tekchips.crl

   R3RS says that (<= x y) is #t if x and y are "monotonically nondecreasing"
   and that (>= x y) is #t if x and y are "monotonically nonincreasing".  I
   interpret this to mean that (<= x y) is equivalent to (not (> x y)), and
   that the following transcript shows correct behavior with respect to the
   unordered case in IEEE standard floating point arithmetic.  Comments?

   >>> (define x (expt 10.0 500.0))
   x
   >>> x
   #<INFINITY>
   >>> (define y (- x x))
   y
   >>> y
   #<NOT A NUMBER>
   >>> (< 3 y)
   #f
   >>> (= 3 y)
   #f
   >>> (> 3 y)
   #f
   >>> (<= 3 y)
   #t
   >>> (>= 3 y)
   #t


I think (<= y 3) and (>= y 3) being #f is more appealing.

(1) This is consistent with the recommended treatment of .GE. and .LE.
    by IEEE standard 754.

(2) "monotonically nondecreasing" does not mean the same thing as
    "not monotonically decreasing".  At least, I didn't think they meant
    the same thing when I put the former in CLtL.

--Guy