Propositional calculus is not the calculus most of us hear about, but is considered by many to be the foundation of symbolic logic. (Actually, the term “calculus” is a generic name for any area of mathematics that deals with calculating; thus, arithmetic could be called the “calculus of numbers.”) Also known as truth-functional analysis, sentential calculus, or the calculus of propositions (or as seen above, any declarative sentence that is either true or false), propositional calculus deals with statements that can be assigned *truth values.* In general, it uses symbols to denote logical operators (such as *and* and or), and parentheses for grouping formulas.