Notas Hellout

https://en.wikipedia.org/wiki/Earley_parser

As seen on [Wikipedia](https://en.wikipedia.org/wiki/Aho%E2%80%93Corasick_algorithm).

https://en.wikipedia.org/wiki/Variation_of_parameters

see - http://en.wikipedia.org/wiki/Computer_algebra_system - http://stackoverflow.com/questions/24311801/symbolic-differentiation-algorithm start with - js-algebra-ast - js-algebra-parse - js-algebra-stringify - js-algebra-differentiation

implement algorithms **0.5**, **0.63** and **0.75**.