> >> 2) We start them with different options, which is why maxima("d2")
> >> just returns d2, but sage.calculus.calculus.maxima("d2") returns the
> >> factorial business that started this thread. Do we want to have some
> >> of the options used to start sage.calculus.calculus.maxima also used
> >> in sage.interfaces.maxima?
>
> >> I also want to point out something that other people may have
> >> realized, but has confused me before: if you're trying to do a
> >> symbolic simplification, and maxima asks you a question, if you do
> >> maxima("assume(x>0)") and try again, it will fail -- because it's
> >> getting sent to the wrong maxima session:
>
> >> sage: sqrt(x^2)
> >> sqrt(x^2)
> >> sage: sqrt(x^2).simplify()
> >> sqrt(x^2)
> >> sage: maxima.assume("x>0")
> >> [x>0]
> >> sage: sqrt(x^2).simplify()
> >> sqrt(x^2)
> >> sage: sage.calculus.calculus.maxima.assume("x>0")
> >> [x>0]
> >> sage: sqrt(x^2).simplify()
> >> x
>
> >> Do other people find this confusing?
>
> > Eventually (if not already) assumptions and the like will need to be
> > recorded and used at a higher level than the maxima interpreter process, so
> > I don't think we could always count on the above working.
>
> They are already recorded at a higher level -- this has been the case
> since 2007.
>
> sage: sqrt(x^2)
> sqrt(x^2)
> sage: assume(x>0)
> sage: sqrt(x^2)
> sqrt(x^2)
>
> Hey wait, WTF?! This is really bad. I don't know what went wrong.
> Evidently there is a new bug.
>
No, this is (somewhere) documented behavior - we don't use the
assumption unless we use Maxima, which is via simplify()
sage: sqrt(x^2)
sqrt(x^2)
sage: assume(x>0)
sage: sqrt(x^2)
sqrt(x^2)
sage: _.simplify()
x
At any rate, that is what assumptions currently do. But it's not a
new bug, at any rate, as far as I know.
- kcrisman
> Anyway, regarding the above, Maxima should *never* need to be
> explicitly invoked or mentioned for using Sage symbolics. Doing so is
> very bad, since it would make is so symbolic user code depends
> explicitly on Maxima. That's not good, since someday Sage's symbolics
> likely won't use Maxima for any symbolic functionality.
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