On Thu, May 5, 2011 at 12:29 PM, Aaron Meurer <[email protected]> wrote: > > > The big questions that remain are those involving (1): it is generally > > accepted that the old assumption system should give way to the new one, > but > > to what extent we remove the old ones from the core? How the new ones > > replace the old ones? What is the syntax that we will use for them? What > > "assumptions" will we make about the assumption system? (i.e., local -vs- > > global context by default) > > Well, one of the biggest problems with having the assumptions in the > core is that any time you want to edit the assumptions you have to > edit the core. Having them separate should make them much more > extensible. >
It's worth picking apart that sentiment. When I say "to what extent we remove the old ones from the core?", I am considering the fact that is_positive may still remain as a function of Expr. The fact that it internally calls an ask(...) of the new assumption system is besides the point. > Also, maybe I am wrong, but I think it would be easier to have > something like Ask(expr, Q.whatever, Assume(x>y)) with the new system. > At any rate, this sort of things cannot be done with our current > is_assumption system (how do you assume x>y using that?). > These are a level of complex assumptions that are out of the scope of what the new assumption system can handle. It requires a higher form of reasoning (potentially FOL, etc). Cheers -- 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.
