Consider integrate(f(x,y),x*y).
do you compute d(x*y) as x*dy+y*dx and compute integrate(f(x) *x,y) + integrate(f(x)*y,x)? Here's another interpretation of variable = x^2... integrate(f(x),x^2) = integrate(integrate(f(x),x),x). that is, an iterated integral. This is like (d ^2 f(x))/dx^2 notation for derivatives, where the derivative is definitely NOT with respect to x^2. Blame Newton, I think, or maybe Leibniz? RJF --~--~---------~--~----~------------~-------~--~----~ To post to this group, send an email to [email protected] To unsubscribe from this group, send an email to [email protected] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
