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+2 votes
2.1k views
asked in Discrete Mathematics by (570 points)  
I think these two statements are similar, can anyone tell me the differences?
  

2 Answers

+2 votes
answered by (116k points)  

Please take a look at the summary of Logic Operations we have, and the precedence of operations. Based on precedence of operation:

¬p¬q=(¬p)(¬q)

and if you look at rule 9 in the figure below, De Morgan's law, we have:

¬(pq)=¬p¬q=(¬p)(¬q)

 

0 votes
answered by  
p q not p not q not p or not q p or q not(p or q)
T T F F F T F
T F F T T T F
F T T F T T F
F F T T T F T

I write a truth table about the question,  you can find that [NOT p OR NOT q] and [NOT(p OR q)]are different.

 
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