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Logic - Derivation Help Please?

  1. Mar 24, 2010 #1
    Do a derivation showing that (P conditional Q) v P is a theorem of system SD+

    *Sorry guys, I can't figure out how to do the symbol in between (P Q), but it means If P then Q and it is otherwise known as the conditional

    -I am really struggling with this problem and I would greatly appreciate any help
  2. jcsd
  3. Mar 25, 2010 #2


    Staff: Mentor

    What is system SD+?

    Make a truth table with separate columns for P, Q, [itex]P \Rightarrow Q[/itex], and [itex]P \Rightarrow Q \vee P[/itex]

    You need four rows.

    To see how I got the "implies" arrow or the V, double-click the expressions that use these symbols, and another window with the LaTeX code opens.
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