Negation of “and” statements: a and b












4












$begingroup$


Is it correct?



$neg$(a and b)=(not a) or (not b)



What ruleset can i look up for negations? Especially for "all", "if, then" statements.










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$endgroup$








  • 2




    $begingroup$
    That is correct. Quatifiers, when negated change to the other, ex $forall$ becomes $exists$. If P, the Q is equivalent to $lnot$ P $lor$ Q. You can use the negation of that to obtain the negation of the implication (if, then).
    $endgroup$
    – RJM
    Oct 23 '16 at 1:02


















4












$begingroup$


Is it correct?



$neg$(a and b)=(not a) or (not b)



What ruleset can i look up for negations? Especially for "all", "if, then" statements.










share|cite|improve this question









$endgroup$








  • 2




    $begingroup$
    That is correct. Quatifiers, when negated change to the other, ex $forall$ becomes $exists$. If P, the Q is equivalent to $lnot$ P $lor$ Q. You can use the negation of that to obtain the negation of the implication (if, then).
    $endgroup$
    – RJM
    Oct 23 '16 at 1:02
















4












4








4


2



$begingroup$


Is it correct?



$neg$(a and b)=(not a) or (not b)



What ruleset can i look up for negations? Especially for "all", "if, then" statements.










share|cite|improve this question









$endgroup$




Is it correct?



$neg$(a and b)=(not a) or (not b)



What ruleset can i look up for negations? Especially for "all", "if, then" statements.







logic






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asked Oct 23 '16 at 0:51









AlucardAlucard

8751627




8751627








  • 2




    $begingroup$
    That is correct. Quatifiers, when negated change to the other, ex $forall$ becomes $exists$. If P, the Q is equivalent to $lnot$ P $lor$ Q. You can use the negation of that to obtain the negation of the implication (if, then).
    $endgroup$
    – RJM
    Oct 23 '16 at 1:02
















  • 2




    $begingroup$
    That is correct. Quatifiers, when negated change to the other, ex $forall$ becomes $exists$. If P, the Q is equivalent to $lnot$ P $lor$ Q. You can use the negation of that to obtain the negation of the implication (if, then).
    $endgroup$
    – RJM
    Oct 23 '16 at 1:02










2




2




$begingroup$
That is correct. Quatifiers, when negated change to the other, ex $forall$ becomes $exists$. If P, the Q is equivalent to $lnot$ P $lor$ Q. You can use the negation of that to obtain the negation of the implication (if, then).
$endgroup$
– RJM
Oct 23 '16 at 1:02






$begingroup$
That is correct. Quatifiers, when negated change to the other, ex $forall$ becomes $exists$. If P, the Q is equivalent to $lnot$ P $lor$ Q. You can use the negation of that to obtain the negation of the implication (if, then).
$endgroup$
– RJM
Oct 23 '16 at 1:02












1 Answer
1






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7












$begingroup$

Yes, that's called De Morgan's Laws. This site has more rules about negations of logical connectives and this PDF should help you with negation of universal and existential quantifiers.






share|cite|improve this answer











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    1 Answer
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    7












    $begingroup$

    Yes, that's called De Morgan's Laws. This site has more rules about negations of logical connectives and this PDF should help you with negation of universal and existential quantifiers.






    share|cite|improve this answer











    $endgroup$


















      7












      $begingroup$

      Yes, that's called De Morgan's Laws. This site has more rules about negations of logical connectives and this PDF should help you with negation of universal and existential quantifiers.






      share|cite|improve this answer











      $endgroup$
















        7












        7








        7





        $begingroup$

        Yes, that's called De Morgan's Laws. This site has more rules about negations of logical connectives and this PDF should help you with negation of universal and existential quantifiers.






        share|cite|improve this answer











        $endgroup$



        Yes, that's called De Morgan's Laws. This site has more rules about negations of logical connectives and this PDF should help you with negation of universal and existential quantifiers.







        share|cite|improve this answer














        share|cite|improve this answer



        share|cite|improve this answer








        edited Jan 24 at 22:57









        Community

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        answered Oct 23 '16 at 1:12









        Noble MushtakNoble Mushtak

        15.3k1835




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