I recognize that it is the empty set described in a different way. Is there a reason why it can't always describe the empty set as [ ] ?
The question I am having is how do I tell if it is the empty set for more complicated inputs? For example, consider setting t1 and t2 to large polynomials computed somehow. Then the following can give an output that is quite large and it is impossible to tell if it is the empty set. Here we know it should be the empty set because of the trivial inequalities given as inputs. But what if the inputs are something meaningful and realistic? sage: g1,g2 = var('g1,g2') sage: t1 = large polynomial sage: t2 = large polynomial sage: solve_ineq([t1 <= t2 , t1 > t2],[g1,g2]) # output that is large and impossible to tell visually that it is the empty set On Monday, December 3, 2012 9:05:57 PM UTC-8, P Purkayastha wrote: > > On 12/04/2012 08:51 AM, Cary Cherng wrote: > > In the below why does solve_ineq called with the inequalities t1 <= t2 , > > t1 > t2 not return [ ], but the other invocations of solve_ineq return > > the empty set as [ ] ? > > > > sage: g1,g2 = var('g1,g2') > > sage: t1 = g1^2*g2^2 > > sage: t2 = g1^2*g2 > > sage: solve_ineq([t1 <= t2 , t1 > t2],[g1,g2]) > > [[g1 == 0, 1 < g2, 0 != 0], [g1 == 0, g2 < 0, 0 != 0]] > > sage: solve_ineq([t1 < t2 , t1 > t2],[g1,g2]) > > [] > > > > sage: s1 = g2^2 > > sage: s2 = g2 > > sage: solve_ineq([s1 <= s2 , s1 > s2],[g1,g2]) > > [] > > > > You have to consider what is in the output. Both the answers contain "0 > != 0", so essentially none of the answers are feasible since "0 != 0" is > always false. > > > > -- You received this message because you are subscribed to the Google Groups "sage-support" group. To post to this group, send email to sage-support@googlegroups.com. To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com. Visit this group at http://groups.google.com/group/sage-support?hl=en.