Logic is the study of the rules which underlie plausible reasoning in mathematics, science, law, and other disciplines.

Symbolic logic is a system for expressing logical rules in an abstract, easily manipulated form.

In algebra, a letter such as x represents a number. Although the symbol gives no clue as to the value of the number, it can be used nevertheless in the formation of sums, products, etc. Similarly P, in geometry, stands for a point and can be used in describing segments, intersections, and the like.

In symbolic logic, a letter such as p stands for an entire statement. It may, for example, represent the statement, "A triangle has three sides." In algebra, the plus sign joins two numbers to form a third number. In symbolic logic, a sign such as V connects two statements to form a third statement. For example, V replaces the...