This is a common technique in designing tests of a system; if you can make a table of inputs and expected outputs, you have a roadmap on what to test. I had a

This is a common technique in designing tests of a system; if you can make a table of inputs and expected outputs, you have a roadmap on what to test. I had a textbook that had a whole chapter about this, I will find the title and edit this post. EDIT: A Practitioner's Guide to Software Test Design, Lee Copeland, Artech House (January 2004), ISBN-13: 978-1580537919.