@Joachim: I really do not understand what are you talking about. As of this moment the solvers in sympy do indeed require you to set your assumptions if you wish solve(x**2-1) to return only +1 and solve(x**2+1) to return None. It would be awful if sympy starts guessing what assumptions the user wants. Every single CAS I know is very explicit about this as it should be.
Moreover, my inquiry is not at all concerned with this question. It is whether solve(x+1) should return [-1] or -1. Even if the abuse of notation of set_of_one_element = the_element_itself is as widely used as you suggest (I do not think so) it is not an abuse of notation that is so important to be supported in a CAS. Your comparison with Principia Mathematica is extreme and I do not think that it is valid. -- 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.
