Boolean Expressions

. compute logical values

. change the flow of control

. boolean operators are: and or not

Boolean expressions are used to compute logical values and as conditional expressions in statements that alter flow of control such as if-then statements. Boolean expressions are composed of the Boolean operators and, or, not - applied to boolean variables or relational expressions.

Relational expressions are of the form E1 relop E2 where E1 and E2 are arithmetic expressions. Boolean expressions can be generated by the following grammar-

E -> E or E | E and E | not E | (E) | id relop id | true | false