Calculator

The main purpose of this example is to show you :

• How to handle business rules using the 'Rule For' Interpreter
• How to use the keyword 'error' to handle exceptions

The simplicity of the Calculator example allows to avoid confusion between the system context and the specific behavior of GreenPepper Software.

Another particularity of this example is that we do not need to write a custom fixture : the Calculator.java class will be use directly.