1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Confused on how to do a simple discrete math problem

  1. Feb 21, 2012 #1
    1. The problem statement, all variables and given/known data

    Use the equivalence [itex]p\rightarrow(r \rightarrow s) \equiv p\wedge r\rightarrow s[/itex] to rewrite the following problem before the proof.

    2. Relevant equations

    [itex][p\rightarrow (q\rightarrow r)]\wedge (p\rightarrow q) \tautologicallyimplies (p\rightarrow r)[/itex]

    3. The attempt at a solution

    [itex][p\rightarrow (q\rightarrow r)]\wedge (p\rightarrow q) \tautologicallyimplies (p\rightarrow r)[/itex]

    1. [itex]p\rightarrow (q\rightarrow r) \equiv p\wedge q \rightarrow r \equiv \neg p \vee \neg q \vee r[/itex]
    2. [itex]p\rightarrow q \equiv \neg p \vee q[/itex]

    3. [itex](\neg p \vee q)\wedge (\neg p \vee \neg q \vee r) \equiv ... \equiv p \rightarrow q\wedge r[/itex]

    What am I doing wrong?

  2. jcsd
  3. Feb 21, 2012 #2
    Does anyone know how to do this proof?
  4. Feb 21, 2012 #3
    Go back to (p and q) -> r. What does p -> q say about the logical value of (p and q)?
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Confused on how to do a simple discrete math problem
  1. Discrete Math Problem (Replies: 4)

  2. Discrete Math Problem (Replies: 1)

  3. Discrete math problems (Replies: 6)