DEFINITION 1 命题逻辑 Let p be a proposition. The statement It is not the case that p. is another proposition, called the negation of p. The negation of p is denoted by p. The proposition a p is read "not p. p的否定 2/24/202111:37PM Deren Chen, ZheJiang Univ 11
L o g i c 命题逻辑 2/24/2021 11:37 PM Deren Chen, ZheJiang Univ. 11 DEFINITION 1. Let p be a proposition. The statement "It is not the case that p." is another proposition, called the negation of p. The negation of p is denoted by p. The proposition p is read "not p." p的否定
EXAMPLE 3 命题逻辑 Find the negation of the proposition Today is friday and express this in simple English The negation is It is not the case that today is friday. This negation can be more simply expressed by i Today is not friday. 2/24/202111:37PM Deren Chen, ZheJiang Univ
L o g i c 命题逻辑 2/24/2021 11:37 PM Deren Chen, ZheJiang Univ. 12 EXAMPLE 3 Find the negation of the proposition "Today is Friday" and express this in simple English. The negation is "It is not the case that today is Friday." This negation can be more simply expressed by ''Today is not Friday
Table 1 命题逻辑 TABLE 1 The truth table for the negation of a Proposition P 2/24/202111:37PM Deren Chen, ZheJiang Univ 13
L o g i c 命题逻辑 2/24/2021 11:37 PM Deren Chen, ZheJiang Univ. 13 Table 1
DEFINTION2 命题逻辑 Let p and g be propositions. The proposition"p and q, denoted by p g, is the proposition that is true when both p and g are true and is false otherwise. The proposition p g is called the conjunction of p and q. The truth table for p g is shown in Table 2. p和q的合取 2/24/202111:37PM Deren Chen, ZheJiang Univ 14
L o g i c 命题逻辑 2/24/2021 11:37 PM Deren Chen, ZheJiang Univ. 14 DEFINITION 2. Let p and q be propositions. The proposition "p and q," denoted by p∧q, is the proposition that is true when both p and q are true and is false otherwise. The proposition p∧q is called the conjunction of p and q. The truth table for p∧q is shown in Table 2. p和q的合取