Criteria in rule is true or false. So when combining criteria together to build the condition part of a rule we need to
clearly understand the Boolean logic, and its operations.
AND / Conjunction
We will use the following notation the dot as operator for AND so A.B is equivalent to A AND B. The conjunction of
two propositions is true when both propositions are true. The truth table is
AND A
B

True

False

True

True

False

False

False

False

OR / Disjunction
We use the + operator for A OR B like A + B. Disjunction of two propositions is false when both propositions are false.
OR A
B

True

False

True

True

True

False

True

False

NOT / Negation
A

NOT A

True

False

False

True

Implication
A> B, implication is a binary operation which is false when A is true and B is false. A > B can be
expressed as NOT A OR B.
A >
B
A
B

True

False

True

True

True

False

False

True

XOR or exclusive OR
Exclusiveor of two propositions is true just when exactly one of the propositions is true
XOR A
B

True

False

True

False

True

False

True

False

De Morgan's Law
De Morgan's law are rules in formal logic relating pairs of dual logical operators in a systematic manner expressed in
terms of negation:
NOT (A AND B) = NOT A OR NOT B
NOT (A OR B) = NOT A AND NOT B
It is important to leverage the De Morgan's law to improve rule writing during the rule transformation.
