This application was originally developed in BASIC in 1973, rewritten in C in the 1980's for use in Computer Science courses, and converted to php and made available on the web in 2005 with minor revisions in 2013 and 2014.
The program converts the Boolean expression into an rpn string, evaluates this string for all possible values of the variables, and generates one line of the resulting Truth Table for each evaluation. While the program can handle all 26 single letter variables, this will result in the impractically large Truth Table with 226 = 67,108,864 lines of output!
The biconditional can be used to show the equivalence of two expressions. As an example, try a&b=b&a; that is, a^b↔b^a. Since all possible values are evaluated, the Truth Table can constitute a rigorous mathematical proof.
Lawrence E. Turner, Ph.D.
Professor of Mathematics and Physics
Southwestern Adventist University