On Sun, Aug 14, 2011 at 4:27 AM, Chris Smith <[email protected]> wrote: > On Sun, Aug 14, 2011 at 3:35 PM, Aaron Meurer <[email protected]> wrote: >> I think Alpha tried to give nice answers. I've never used >> Mathematica, but I suspect it would be a little more rigorous about >> assumptions, as Maple is and as we should be. > > Alpha gave the correct unsimplified answer but also offers expressions > "when all symbols are positive" (and it clearly notes such). I didn't > mean it gave an answer that was only valid if the symbols were > positive. > >> If the combination is valid (and if it's not we should reconsider how >> we do auto-combination in Mul.flatten), then powsimp should be able to >> do it. > > I'm loosing track of what you are referring to, the original > expression or the expression for when x and y are positive? I don't > think there is anything invalid coming from flatten; flatten just > doesn't look for how Mul bases under Rationals can be joined with > existing items in the sequence being flattened. I've added a routine > to the powsimp module to patch up the sub-optimal Mul.flatten result. > (It's in my `and` branch.) >
The original expression with vanilla symbols. I know Mul.flatten doesn't combine this one, but we need to double check things if a.base*a == a.base**(3/2) is not really valid for all x and y. But I rather suspect that it is valid. Aaron Meurer -- You received this message because you are subscribed to the Google Groups "sympy" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/sympy?hl=en.
