Evaluator parses all arithmetic expressions using only one ASD grammar --expression.grm.  The grammar is automatically loaded at start up so there is no need to type it in manually.  Evaluator has been recently upgraded to run on Java 8. A new User Interface class has been added and parts have been refactored. The UI has been improved again. The logic (from Prof. Jim Mason) however was not modified.  All the sources are on GitHub .  Here below is the OpenWebStart launch: