On 24 May 2007 20:09:32 +0200 Martin Rubey replied to: Sumant S.R. Oemrawsingh who wrote:
I just find this very strange: (1) -> %e (1) %e Type: Expression Integer (2) -> %pi (2) %pi Type: Pi Why is %e of type Expression Integer, while %pi is of type Pi? Is there some deeper reason why Pi is its own type?
For some reasons, the original developers of axiom found %pi more important than %e. For elements of Expression Integer there is no direct conversion to Float, so they created an own domain HackPi?, which contains only %pi and the necessary conversion functions. The didn't want to do the same thing with %e though:
(2) -> %e::Float Cannot convert from type Expression Integer to Float for value %e
In my opinion, we should have a domain for "general" constants, i.e., like Expression Integer but without variables, and, more generally, a domain for expressions with a given set of variables, similar to MPOLY. But I guess, that's a fair bit of work.