I have a function f(x) that I do not want to be expanded but wish to evaluate the partial derivative of g(x,f(x),...) with respect to x, I can not figure out how to declare the function and indicate it is a function of x without an explicit definition.
Code example:
var("x")
f = ??? # how do I define this?
g = x * f(x)
g.diff(x)
Expected output:
x * f'(x) + f(x)
