We use the **muparser** math library.

There are functions available, like **abs()**
There are built in constants, like **_pi**
Also, there is an ‘if then else’ construct, example: “if (a > b) then y else z” is expressed by: **( a > b : y | z)**

See these links for more info on what you can find in **muparser**:

Built-in operators:
http://beltoforion.de/article.php?a=muparser&hl=en&p=features&s=idDef1#idDef1

Binary operators:
http://beltoforion.de/article.php?a=muparser&hl=en&p=features&s=idDef3#idDef3

Ternary operators (if then else):
http://beltoforion.de/article.php?a=muparser