I guess this is the dependency problem in interval arithmetic: https://en.wikipedia.org/wiki/Interval_arithmetic#Dependency_problem (Note that x**2+x is the example used there)
The issue is that we have to know the identity of the intervals. For example if x and y are distinct intervals both [-1,1] then x*y is [-1,1]. However x**2 has to be [0, 1]. On Sat, 20 Jul 2019 at 11:34, Chris Smith <smi...@gmail.com> wrote: > > Which result is correct? The second is a refactoring of the first: > > >>> AccumBounds(-1, 1) + AccumBounds(-1, 1)**2 > AccumBounds(-1, 2) > >>> AccumBounds(-1, 1)*(1 + AccumBounds(-1, 1)) > AccumBounds(-2, 2) > > -- > 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 sympy+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/sympy/e9b71b7d-8239-4851-8358-23b1249dbd7a%40googlegroups.com. -- 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 sympy+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/CAHVvXxSbb4VLZa01JU92c3%3DuA8gxQdcZZirXF5b9D%3DCsnxng4Q%40mail.gmail.com.
