On Tue, Jan 19, 2016 at 7:57 AM, Oscar Benjamin <[email protected]> wrote:
> On 18 January 2016 at 20:47, Aaron Meurer <[email protected]> wrote: > >>> For now, I would recommend using the old assumptions. However, you can > >>> play with the new assumptions. The goal in making the new assumptions > >>> read the old was to make this easier to do. > >> > >> But it also makes it a confusing mish-mash of the two. What's the > >> eventual goal here? > > > > The eventual goal is to merge the two, so that one calls the other. > > Then it won't matter which one you use. It will just be a question of > > which syntax you prefer. For now, we have that in one direction (the > > new system calls the old). > > Okay I get it now. So the plan is not really to have two systems or to > deprecate one but just to have two APIs for using assumptions. The > name "old assumptions" lead me to assume that when the new system was > ready the previous would be deprecated and removed. > That was the original plan. But we've come to realize that it's untenable. > > I do prefer the the new assumptions API so I would consider it an > improvement when it's ready. Of course there will be some cases where > you need to attach assumptions to objects because of > auto-simplification. There was a recent thread about using > commutative=False to prevent (a*b)/(a*c) from automatically > cancelling. I guess there's no new-style way to do that? > Cancellation isn't something that has been part of the assumptions system thus far. It happens automatically in the Mul constructor. I'm not sure if it really makes sense to try to solve this problem with the assumptions system. It's already a bit of a stretch to include commutative=False in the assumptions system. Aaron Meurer > > -- > Oscar > > -- > You received this message because you are subscribed to the Google Groups > "sympy" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at https://groups.google.com/group/sympy. > To view this discussion on the web visit > https://groups.google.com/d/msgid/sympy/CAHVvXxQUB_eAmuu7OLQJfT%3DS4Zy2Q_7xh9fPkDDtO68zCpjYSg%40mail.gmail.com > . > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/sympy. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/CAKgW%3D6%2BNeiFoZopAjPMt0P-4rtZd%2B1BwJdtbwz4E_81%3DJUBuCA%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
