Math Parsers for Unity 5.1.4 and .NET 2.0 or Mono for Unity

Has anybody used Math Parsers with Unity before. I tried several but they don’t seem to be compatible with .NET 2.0?

On the other hand is there some build in function to calculate mathematical expressions like:

“2 + 3 * 5 - 4” = 13

More info here: c# - How to structure program that calculates math expression - Stack Overflow

This is made by some Alek: http://mono.1490590.n4.nabble.com/Javascript-eval-function-in-c-td1490783.html

It uses variant of the eval() function. It works.
Try: Debug.Log(Evaluator.eval(“2 + 3 * 5 - 4”));
it prints 13.