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  •  » question about how to determine Tautologies, Contradictions & Continge

#1 2011-07-07 06:21:31

dangermulan1988
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question about how to determine Tautologies, Contradictions & Continge

please delete

Last edited by iwan_ccie (2011-07-11 23:38:34)

 

#2 2011-07-07 07:49:12

anonimnystefy
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Re: question about how to determine Tautologies, Contradictions & Continge

hi iwan_ccie

first one is a contradiction

second one is a contradiction

third one is a tautology

fourth one is contingent

and the fifth one is also contingent.


The limit operator is just an excuse for doing something you know you can't.
“It's the subject that nobody knows anything about that we can all talk about!” ― Richard Feynman
“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment
 

#3 2011-07-07 07:57:16

anonimnystefy
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Re: question about how to determine Tautologies, Contradictions & Continge

hi iwan_ccie

there are several ways to determine if a proposition is a tautology or a contradiction.
the easiest one is to make a table,make columns for all the boolean variables and then plug them into the equation and if the equation is always true then it is a tautology,and if it is always incorrect than it is a contradiction.
the other one works only when you have to prove that it is a tautology.it is called reductio ad absurdum.


The limit operator is just an excuse for doing something you know you can't.
“It's the subject that nobody knows anything about that we can all talk about!” ― Richard Feynman
“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment
 

#4 2011-07-07 08:07:06

dangermulan1988
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Re: question about how to determine Tautologies, Contradictions & Continge

Thanks for your answer!

So you created truth tables?
Can you show me how you did this? And how you determined the answers?

 
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