Page 11 - Chapter 2
P. 11

• The negation of Quantifiers ∀ & ∃




    (a)   let p: ∀x P(x),




    then  ~p: there must be at least one value of x


 for which P(x)  is false, namely,



                              ~ ∀x P(x) = ∃x ~P(x)








     (b)  let p: ∃x P(x),



        then ~p: for all x, P(x) is false, namely,



                                ~ ∃x P(x)= ∀x ~P(x)
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