Comment #31 on issue 1694 by asmeurer: solve has many issues with fractions http://code.google.com/p/sympy/issues/detail?id=1694
I think that we should not return infinities from solve. If solve returns something, I expect it to be a root that actually exists. Singularities should, in my opinion, be handled by limit. So in this case, you could do something like: In [62]: limit(solve(exp(x) - y,x)[0], y, 0) Out[62]: -∞ And it also works in the other example you cite: In [64]: limit(solve(1/x - y,x)[0], y, 0) Out[64]: ∞ Any idea where solve is returning oo there? My guess is that it is doing something much like my limit example above only with direct evaluation, i.e., In [65]: log(0) Out[65]: -∞ -- You received this message because you are listed in the owner or CC fields of this issue, or because you starred this issue. You may adjust your issue notification preferences at: http://code.google.com/hosting/settings -- You received this message because you are subscribed to the Google Groups "sympy-issues" group. To post to this group, send email to sympy-iss...@googlegroups.com. To unsubscribe from this group, send email to sympy-issues+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/sympy-issues?hl=en.