In propositional calculus and Boolean algebra, a truth table is a two-dimensional array with columns used to show the truth value of a logical expression made up of propositions P, Q, … (sentences with a True or False value). The first columns correspond to the possible values of the inputs and the last column to the truth value for the given expression. This Demonstration produces truth tables for the logical operators And, Nand, Or, Xor, Implies and Not acting on expressions with two to seven propositions, each of which may be True or False. A shuffle option returns an expression with alternated logical operators of length .