Donna: Let me try to summarize some of this discussion and suggest a direction to move forward.
Any computer can represent only finitely many numbers. Whether they be integer, floating point, or rational, there are infinitely many quantities than cannot be represented exactly. There is nothing special about J in this regard: any language has similar expressiveness and limitations, although the details will vary. As a side issue, a programmer can represent a rational number as a numerator/denominator pair without canonicalization: this is an implementation decision, and has nothing to do with the language. Questions about representations of numbers can be answered through reference to any familiar language. There are techniques that can be used to obtain accurate results despite these limitations: this is what numerical analysis is about. If you are interested in linear programming (I'm not sure if you are, or whether you were just citing an example), you might want to take a look at http://www.jsoftware.com/jwiki/Stories/RichardBrown which contains an annotated description of using the simplex algorithm in J. More generally, you will probably learn more from trying a solve a familiar problem in J than from any amount of discussion here. Otherwise it is like trying to understand swimming by talking about it rather than getting your feet wet. Best wishes, John ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
