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Homework Help: Help with logic proof (this should be really basic)

  1. Nov 4, 2008 #1
    help with logic proof (this "should" be really basic)

    Hey I am new to logic (I've just started a masters)

    I can't for the life of me prove this using only the natural deduction inference rules:

    A --> B |- ¬A v B

    I can do it easily in the other direction but I cannot do it in the above direction.

    It's annoying as I can do it easily using truth tables!

    Any help much appreciated.

    1. The problem statement, all variables and given/known data

    2. Relevant equations

    3. The attempt at a solution
  2. jcsd
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