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CHAPTER 10 /BASIC TECHNOLOGY OF THE INTELLIGENT COMMUNICATION SYSTEM 1 1 1
TABLE I O.I Logical Operation
p q p*q pvq ~q p**q p-*q
T T T T F T T
T F F T T F F
F T F T F F T
p p F F T T T
TABLE 10.2 Operation of ~p v q
p q ~pyq
T T T
T F F
F T T
F F T
"v" is a disjunction.
"—»" is an implication.
"<->" is an equivalent.
The definitions of these operators are shown in Table 10.1.
Table 10.2 shows that the operation "~p v q" is equivalent to the operation "p -» q."
The following are true of a logical expression.
(1) Both an atomic formula and a negation of an atomic formula are logical
expressions.
(2) A formula of logical expressions connected by an operator or operators
is a logical expression.
(3) Only a formula defined as in items (1) and (2) is a logical expression.
The operation rules governing logical expressions are as follows:
