BT MATH
A simple implementation of an expression evaluator that can handle basic arithmetic operations, parentheses, and some mathematical functions that provide a way to evaluate mathematical expressions using RPN (Reverse Polish Notation) implemented in two parts: parsing and evaluation.
```
let expression = "2 + 3 * 4";
.......
let f = evaluate_expression(expression).unwrap();
```
* *
GPL-3.0-only