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Proving a tautology using truth table

  • Thread starter MarcL
  • Start date
  • #1
170
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Homework Statement


((p_r)^(q_r))<-->((p^q)_r) Prove whether the following statement is a tautology , contigency or contradiction using a truth table.

Homework Equations




The Attempt at a Solution


I did the truth table, but this whole thing is one statement no? What do I compare? the first half of the bi conditional statement to the second? or the whole statement vs. the two halves? I don't know which to compare to decide whether or not it is a contingency.


EDIT: figured out the tautology is if L.H.S of <--> is equal to RHS. Sorry for the post!
 

Answers and Replies

  • #2
130
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Just a question for you, what is ^ and _? In the logic courses I took, we used different symbols and I'm aware different schools/fields use different symbols so just wanted to know what yours are. Thanks :)

Btw I'm guessing ^ is conjunction and _ is disjunction?
 
  • #3
170
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Well I used ^ for conjunction ( so AND) and _ for inclusive or because I can't the the opposite of ^ :) ( it was my own guess)
 
  • #4
130
30
Well I used ^ for conjunction ( so AND) and _ for inclusive or because I can't the the opposite of ^ :) ( it was my own guess)
Ah, alright :D If you click the sigma Σ button on the toolbar, there are many symbols to choose from including ∧ ∨ ⊃ ⋅ ∴
 

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