On Wednesday, September 21, 2005 8:52 AM Martin Rubey wrote: >... > Well, output is easily changed.
Yes, you are right. As usual, I just wish we had more documentation: both user documentation (how-to) and conceptual documentation (why). Axiom's approach to output as a coercion to the type OutputForm is radically different than any other computer algebra system that I know. There is an attempt also in Axiom to do the same with input (InputForm and SExpressions etc.) This is a powerful idea that depends centrally on the strong typing system. Understanding how to use types and domains in Axiom is both "90% of the problem" and "90% of the reasons why one might want to use Axiom in the first place". We need to write more about this ... > You did notice that the *real* power of different > representations is speed. I wrote a short note about the concept of representation in Aldor (which also applies to Axiom and SPAD) http://wiki.axiom-developer.org/RepAndPer I think that you are right that one of the main points about different representations is the relative computational efficiency of different implementations for different purposes. But I think there is much more to this concept and that the current Aldor and SPAD syntax does not sufficiently highlight the important place that it holds. The current syntax, i.e. 'rep' and 'per' as macros and 'Rep' as a distinquished name for a local domain, seems to treat representation on a par with other programming constructs. > Thus, my domain is rather cosmetics, however useful it > may be. We do agree that cosmetics is useful, I guess. > I just spent a couple of hours trying to add a new operation called 'terms' to the DistributedExpression domain. The idea was that it should return a List of Expressions in analogy with the 'monomials' operator of POLY, but I kept getting hung up on vague SPAD compiler messages and picky details for explicitly specifying domains... After all this time I still do not feel fluent in SPAD/Aldor but for some reason I continue to admire it greatly when I see something that works! :) Yes, I do agree that "cosmetics" is useful. In fact I have been know to claim that "notation is (almost) everything" in mathematics and I think that applies equally to computer algebra systems. Regards, Bill Page. _______________________________________________ Axiom-developer mailing list [email protected] http://lists.nongnu.org/mailman/listinfo/axiom-developer
