
Analitza:
- Partial derivatives
- Simplification for x^3*3/x-> 3*x^2

Expression:
- Copy on write for m_tree

2D:
- Shared functions Console <-> 2D
- Sort 2D functions
- Moving on small viewport step is too large.
- Review keyBindings for zooming out.

Doc:
- Document about piecewise
- Document about anything else
