Equation abstraction layer

[Pituivan]

The thing I will be doing the most in this repo is undoubtedly transforming mathematical equations.

I already implemented some helpers for equation derivation in #2, and that had saved an insane amount of time. Building a system for easily managing and transforming members in equations individually will unarguably be worth it.

[Pituivan]

I could add that to a new core/ package