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not, and, or

boolean operators

Syntax
not E
E and F
E or F

where E and F are of type BOOL.

Description
These operators have their usual meanings. Note that when two or more boolean expressions are combined with AND, they are evaluated one by one until a False expression is found. The rest are not evaluated. For example, given the expression A and B , the system does not attempt to evaluate B unless A evaluates to True. Similarly, evaluation of a sequence of boolean expressions connected by OR stops as soon as a True expression is found.