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#1 2009-12-05 09:57:08

dheeraj
Guest

conditional statment

prove that
Эx(P(x)^Q(x)) →Э(x)P(x) ^Э(x)Q(x) is a tautology .

#2 2009-12-13 06:16:59

rzaidan
Member
Registered: 2009-08-13
Posts: 59

Re: conditional statment

Hi dheeraj;
this is a conditional statment which is true except when the condition is true and the result is false(i.e the statment p⇒q is always true except when p is true and q is false ) , but this case does not hold since when Эx(P(x)^Q(x)) is true means that  Э(x)P(x) ^Э(x)Q(x)  is true too . Therefore Эx(P(x)^Q(x)) →Э(x)P(x) ^Э(x)Q(x) is a tautology .is a tautology .
Best Regards
Riad Zaidan

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