coolSCV
The idea is what is important though. Recursive descent parsing uses the functions that correspond to types in the grammar to mutually call each other thus parsing the expression recursively in a descending fashion.
https://gist.github.com/ascv/5022712
The idea isn't to 1-up the OP but rather to showcase the technique of recursive descent parsing. The wikipedia entry for recursive descent parsing also has a very nice example.
However as an example, if someone is solving linear or non-linear programs using <insert software or library here> but hasn't bothered to thoroughly study the mathematics underlying either and is just plugging in numbers from the constraint equations they came up with, then I would not want that person doing any sensitivity analysis. There would just be no way to be confident that they are interpreting the results correctly.
Nicely worded. I think the real issue is that many people want mathematics to be easy to read and understand. Unfortunately, much of mathematics is not easy to read nor is it easy to understand regardless of how it is written. Mathematics, like many other things, often requires a lot of intellectual scaffolding to be built from the bottom up. There is no shortcut to the top.