Results 1 to 3 of 3
Like Tree1Thanks
  • 1 Post By Soroban

Math Help - propositional logic: prove or disprove

  1. #1
    Newbie
    Joined
    Mar 2012
    From
    Australia
    Posts
    20

    propositional logic: prove or disprove

    i'm supposed to prove (p → q) ∧ (p → r) ⇒ (q ∨ r) with a truth table and im stuck. i've created most of the truth table by hand. but i do no know how to prove or disprove it.
    any help is much appreciated.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Super Member

    Joined
    May 2006
    From
    Lexington, MA (USA)
    Posts
    11,909
    Thanks
    767

    Re: propositional logic: prove or disprove

    Hello, nehal234!

    I don't understand your difficulty.


    i'm supposed to prove (p → q) ∧ (p → r) ⇒ (q ∨ r) with a truth table and im stuck.
    i've created most of the truth table by hand. . Most if it? . . . What does that mean?
    But i do no know how to prove or disprove it. . Do you understand what a truth table does?
    . . \begin{array}{|c|c|c||cccccccccccc|} p & q & r & [(p & \to & q) & \wedge & (\sim p & \to & r)] & \to & (q & \vee & r) \\ \hline T&T&T & T&T&T&T&F&T&T&{\color{red}T}&T&T&T \\T&T&F & T&F&T&F&F&T&F&{\color{red}T}&T&T&F \\ T&F&T & T&F&F&F&F&T&T&{\color{red}T}&F&T&T \\ T&F&F & T&F&F&F&F&T&F&{\color{red}T}&F&F&F \\ F&T&T & F&T&T&T&T&T&T&{\color{red}T}&T&T&T \\ F&T&F & F&T&T&F&T&F&F&{\color{red}T}&T&T&F \\ F&F&T & F&T&F&T&T&T&T&{\color{red}T}&F&T&T  \\ F&F&F & F&T&F&F&T&F&F&{\color{red}T}&F&F&F \\ \hline &&& 1&2&1&3&1&2&1&4&1&2&1  \end{array}
    Thanks from nehal234
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Mar 2012
    From
    Australia
    Posts
    20

    Re: propositional logic: prove or disprove

    i see how you have used ⇒ and → to be the same. this makes it clear for me.
    thanks
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. propositional logic
    Posted in the Algebra Forum
    Replies: 2
    Last Post: August 30th 2011, 10:52 AM
  2. Propositional Logic
    Posted in the Discrete Math Forum
    Replies: 1
    Last Post: March 20th 2011, 05:46 AM
  3. propositional logic
    Posted in the Discrete Math Forum
    Replies: 12
    Last Post: August 3rd 2010, 12:52 PM
  4. Replies: 1
    Last Post: March 27th 2009, 07:43 AM
  5. propositional logic
    Posted in the Discrete Math Forum
    Replies: 5
    Last Post: June 10th 2007, 10:50 AM

Search Tags


/mathhelpforum @mathhelpforum