"Bill Page" <[EMAIL PROTECTED]> writes: | On April 1, 2007 5:45 AM Gaby wrote: | > | > >> Why should InputForm be preferable over Expression T? | > >> | > ... | > > For me to answer your question it is important to understand | > > what Expression in Axiom really is. One way to do that is to | > > look at the internal representation. | > > | > > Rep:=Fraction SparseMultivariatePolynomial(T, Kernel %) | > > | > > So Expression is a mathematical domain of rational functions | > > (ratio of two polymonials) where the polynomial variables | > > are extended to kernels including various special functions. | > | > Sorry, I don't think I'm satisfied with an answer that has to | > look at the internal representation before explaining why I | > should not believe the interface. | > | | Of course you should believe the interface! There is no need to | look at the internal representation.
I very much prefer an answer in terms of interfaces than that of internal representation (where possible). Because interfaces are what explains the thingies to us -- even as developers. | I just thought it might be | easier since we are developers and are able to take a "white box" | view. I regret to say, but I'm a big fan of encapsulation (where useful) and prefer to see interfaces even if I'm spending all my time tweaking in the innards. Thanks for the illustation. The difference, as I see it comes from the larger number of supported mathematical operations for Expression T, than there are for InputForm. Augment InputForm with all useful mathematical operations working on InputForm and you'll see very little difference from Expression T. Hence, Martin's warning. Also, be aware than the Axiom designers, in many places, thought of Expression as the general domain for symbolic manipulation and have appropriate hardwired type inference rules in the interpreter. -- Gaby _______________________________________________ Axiom-developer mailing list [email protected] http://lists.nongnu.org/mailman/listinfo/axiom-developer
