[Maxima] Representation of floats

[Steve Haflich]

   I don't see: where is rounding? Firefox up to k=22 returns exact values

Stavros already made this point, but perhaps not sufficiently: You must
keep firmly in mind the difference between "return" and "print".  They
are not the same.(*)

Volker commented:

   (%i2) if (0.2+0.2+0.2 = 0.6) then "yes" else "no";
   (%o2)                                 no

A more direct illustration would be the following, which you can try in
your favorite Common Lisp:

   (= 0.6 3/5) => NIL

I believe this result is _required_ by the ANS, at least if
:ieee-floating-point is present on the *features* list.

(*) See also http://en.wikipedia.org/wiki/The_Treachery_of_Images