On Mon, 23 Mar 2009, Robert Dodier wrote:
< On Thu, Mar 5, 2009 at 12:32 PM, Barton Willis <willisb at unk.edu> wrote:
<
< > In the context of hypergeometic functions, I've been thinking about
< > this problem too. For every identity in Abramowitz and Stegun and
< > Gradsteyn-Rhyzik do we want to invent a name for the rule? What would
< > that look like and how useful would it be? How could we organize this
< > so that it is useful and easy to use?
<
< Hmm, I like the idea of making a look-up table of identities,
< identified by some abbreviation like "A&S 1.2.3" (I think just
< the number is not enough).
<
< I've tinkered with some macros to make rules more
< readable e.g. foo(x, y) --> bar(y) - bar(x) when (bazp(x) and quuxp(y))
< (stuff following "when" expand into matchdeclare's and the
< "-->" expands into a rule definition).
<
< So we could have stuff like
<
< identities["A&S 1.2.3"] : foo(x, y) --> bar(y) - bar(x) when (bazp(x)
< and quuxp(y));
<
< and then
<
< expand_foo (e) := apply1 (e, identities["A&S 1.2.3"], identities["A&S 1.2.7"]);
<
< There's a certain amount of wishful thinking here,
< but maybe this can provide some kind of inspiration.
You may be aware that NIST is currently producing an online, updated
A&S. Some parts are now available
http://dlmf.nist.gov/
Leo
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