#LED The Language of Effective Definitions (LED) is a formal language for writing computable functions, designed by Dr. Nelson Rushton at Texas Tech University and implemented by Dr. Qianji Zheng LED can be used as a functional programming language, as a tool for teaching mathematics and functional programming, or as a medium for precise human-to-human communication of mathematical definitions. It is used as a teaching tool in Dr. Rushton's CS 1382 Discrete Math class. The design goals of LED are rigor, imitation, and simplicity, defined as follows:

1. rigor: The syntax and semantics of the language are explicitly and precisely specified.
2. imitation: LED expressions denote traditional mathematical objects (numbers, symbols, sets, tuples, and functions) using notations customary in technical and educational literature, as closely as possible while writing plain text.
3. simplicity: Someone familiar with functional programming, or with the conventions of mathematical notation, can learn to read LED programs before breakfast, and learn to write them before lunch. #Requirement Python 3.4 #File Dependency
4. Tokenizer, called Tokenizer.py
5. Expression data type, called Expression.py
6. Program data type (depends on 1), called LEDProgram.py
7. Evaluater (depends on 1,2), called Evaluater.py
8. Parser (depends on 1, does not include program parser), called Parser.py
9. Compiler (that is, the program parser. depends on 1-4).
10. Game engine (depends on 1 , 2, 3), called EaselLED.py.
11. Interface (depends on 1-6), called IDE.py.

#Mini Tutorial

1. Download and install Python 3.4.
2. Download the files in the repository.
3. To start the LED interpreter, double-click the file IDE.py. After the console is shown, enter run(test) to compile if test.led is a LED program. Enter play(tttftb) to run a game if tttftb.led is a LED game program.
4. For "Syntax of expressions" and how to evaluate experssion using LED, please refer to the file LEDTutorial.pdf

#Contributors

• Dr. Nelson Rushton, Texas Tech University
• Qianji Zheng, Ph.D. student, Texas Tech Univeristy