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Math Help - Proof by contradiction.

  1. #1
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    Proof by contradiction.

    Use Boolean algebra to show that ((p^q) implies (p implies q)) is a contradiction. do not use truth tables, thanks.
    different question!!
    Last edited by mr fantastic; August 20th 2011 at 05:45 PM. Reason: Deleted begging in title.
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  2. #2
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    Re: Proof by contradiction (please help, urgent) :)

    Are you sure this expression is a contradiction? For me it is a tautology!
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  3. #3
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    Re: Proof by contradiction.

    I get a tautology too:

    ((p\wedge q) \longrightarrow (p \longrightarrow q))

    \equiv (-(p\wedge q)\vee (-p \vee q))

    \equiv (-p\vee-q)\vee (-p\vee q)

    \equiv -p\vee T

    \equiv T

    Therefore it's a tautology.
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  4. #4
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    Re: Proof by contradiction.

    That is exactly what I found!
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