Basic vector code, without a coordinate system class

All calculations essentially occur in the same frame.
i, j, k and x, y, z are imported as base vectors and base scalars by default on importing sympy.vector.
delop is a Del operator instance.

Example:

>>> v = 3*i - j
>>> delop ^ v
0

(delop ^ v represents curl of v)
I'm not really a fan of overloading `^` and `&` and never liked it in the current Vector module. I see how it can make the code shorter and maybe more mathematical. As far as I know, only the geometric algebra module in sympy does this.

Are there other instances in sympy where this is done?