Type a sentence in propositional logic into the input field and press compute. This should result in the truth table for the given sentence being computed and displayed. Note that this takes time exponential in the number of propositional variables.
The syntax for the input is a KIF-like language. Atoms are words. Non-atomic sentences must be surrounded by brackets and the connective is the first element of such a list. The possible connectives are "not" (which is unary), "and", "or", "=>", and "<=>". An example of a syntactically correct sentence is:
(=> (and P Q) (<=> R (not S)))
C.-L. Chang and C.-T. Lee. Symbolic Logic and Mechanical Theorem Proving, chapter 2. Academic Press, 1973.