3.4 Boolean Expressions

Boolean operations are also legal. (POSIX bc does NOT have boolean operations). The result of all boolean operations are 0 and 1 (for false and true) as in relational expressions. The boolean operators are:

!expr

The result is 1 if expr is 0.

expr && expr

The result is 1 if both expressions are non-zero.

expr || expr

The result is 1 if either expression is non-zero.