# logical operation

A logical or Boolean operation on *N*-state variables is one that yields a single *N*-state variable;
e.g., a comparison on the 3-state variables *A* and *B*,
each represented by –, 0, or +, which yields: - when *A* is less
than *B*, 0 when *A* equals *B*, and + when *A* is greater than *B*. Specifically, operations such as AND, OR,
and NOT on two state variables which occur in the algebra of logic;
i.e. Boolean algebra.

Logical operations are also the operations of logical shifting, masking, and other non-arithmetical operations of a computer.