On 4/17/08, David Ronis <ronis at ronispc.chem.mcgill.ca> wrote:
> I define a function C(s,sp):= A(s+sp)+B(s,sp)+B(sp,s); where A and B
> are defined earlier in the code. Clearly, C(s,sp) should be symmetric
> in s and sp. However, if I simply type C(s,sp) at the maxima prompt,
> what I get isn't. On the other hand, C(x,y) is.
Well, I get is(C(s, sp) = C(sp, s)) => true. Doesn't that mean C is
symmetric? Maybe I am missing something here. What does
C(s, sp) - C(sp, s) yield when you try it?
It seems plausible that binding s to 'sp and sp to 's (by the function
call C(sp, s)) could cause strangeness in evaluation,
but I don't actually see any strangeness.
> P.S., one last thing, is there some what to tell maxima that a function
> is positive? I don't think that I should have to have copies of some of
> the assumes.
declare recognizes posfun (e.g. declare(foo, posfun)) but I don;t know if
the simplifier can do much with it.
best
Robert Dodier