Hi everyone. I'm concerned about how subs() handles dictionaries, in which the values of the dict contain some of the keys, such as
(x**2+y**3).subs({x: a*x+b*y, y: b*x-a*y}) Would it be preferable that the result is (a*x+b*y)**2+(b*x-a*y)**3 ? Right now subs() re-substitues terms which were already substituted (a*x+b*y)**2+(b*(a*x+b*y)-a*y)**3 , which seems especially strange, since the dictionary does not imply any order for the substitution. I think, if I would like to resubstitute substituted terms, I would simply apply subs() several times (x**2+y**3).subs({y: b*x-a*y}).subs({x: a*x+b*y}) A possible solution would be to uniquely change the names of all variables which are to be replaced internally, then do the substitution given as dictionary and then rename everything back. Would this be a useful thing to have? Thanks, Martin -- You received this message because you are subscribed to the Google Groups "sympy" group. To post to this group, send email to sympy@googlegroups.com. To unsubscribe from this group, send email to sympy+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/sympy?hl=en.