Combining exponents is such a common operation that not doing so would be a huge burden on the whole system. I think you'll just have to put a note in the continuous_domain docstring that this sort of thing happens.
Aaron Meurer On Thu, Jun 23, 2016 at 6:27 AM, Kshitij Saraogi <[email protected]> wrote: > While developing the methods for determining the domain and range of the > given function, > I stumbled across the following particular case: > > In []: x = symbols('x') > > In []: x/x > Out[]: 1 > > In []: (x-1)**2/(x-1) > Out[]: x - 1 > > In []: (x**2 - 2*x + 1)/(x-1) > Out[]: (x**2 - 2*x + 1)/(x - 1) > > Having read this wiki, I know that automatic simplification is a known > issue. > > In the case of determining domains, this leads to incorrect results. > For example, > > In []: continuous_domain(x/x, x,S.Reals) > Out[]: (-oo, 0) U (0, oo) > > However, with the automatic simplification, this is not quite the case. > The function `x/x` gets automatically simplified to `1` which does not take > into account the singularity at x = 0. > > The same situation arises with the case of `(x - 1)^2/ (x - 1)` which > simplifies to `x - 1`. > > I would like some inputs on handling these issues. > > -- > 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/65fc3b03-cdb9-450b-b2f9-2e4cd402d846%40googlegroups.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%3D6KQ__BmXUzrx2JBnSopUFV%3DfJ7_Uo%2Bb%2BqBd48B%3DJPNipQ%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
