Hi Roland, On 21 Jul., 14:54, Rolandb <rola...@planet.nl> wrote: > Simon, thanks!
You're welcome! > But in general there is no (Sage) algoritm to simplify expressions > given some equalities? If I remember correctly: If the equations are not polynomial but anything (e.g. "sin(x)*y=cos (z)" and so on) then one can prove that there is no algorithm that would cover all consequences of the given general relations. You can always do substitutions, as pointed out by Stan, but this would only be a syntactical operation. So, if you replace x+y by 0, then the 'subs' method would not realize that x^2+x*y is zero as well: sage: var('x y') (x, y) sage: (x^2+x*y).subs_expr(x+y==0) x^2 + x*y Cheers, Simon Cheers, Simon --~--~---------~--~----~------------~-------~--~----~ 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 For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---