Simon King wrote: > Dear Jason, > > On Dec 3, 7:54 pm, Jason Grout <[EMAIL PROTECTED]> wrote: >> Wow, Sage will redefine symbols that are already existing to accommodate >> what should be a dummy variable? This looks seriously wrong and looks >> like it could really mess things up. > > I don't think so. Admittedly I don't like that x is pre-defined, but > here it is something else. > There are Sage constructions which define various things in one line. > For example, > sage: R.<z>=QQ[] > both defines R *and* z (the latter of type Polynomial_rational_dense).
In this case, z is not being used as a dummy variable. I think it makes a lot of sense to define z globally when z is on the right, versus defining z just locally when you have R = QQ['z'] > > Similarly, doing > sage: R(z)=sin(z) > both defines R *and* z (the latter of type SymbolicVariable). In this case, mathematical convention says that z is a dummy variable; it should not matter what I call the thing inside the parentheses, and it certainly shouldn't affect stuff outside of the function. Maybe part of the huge difference in my mind is that R(z) = sin(z) tries to follow a deeply-ingrained mathematical convention, while R.<z> is defining new notation. Jason --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
