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# propositional logic tricky question Watch

1. Can someone please give me an example of a statement about something in the world that can't be a contradictionn, tautology nor a contingent?

2. Looking at the definition of contingent, http://en.wikipedia.org/wiki/Contingent
In philosophy and logic, contingency is the status of propositions that are neither true under every possible valuation (i.e. tautologies) nor false under every possible valuation (i.e. contradictions).
So a proposition has to be either a contradiction, tautology or a contingent.
3. Is this not by definition impossible?
Not a tautology means not neccessarily true.
Not a contradiction means not neccessarily false.
Which by definition makes it a contingent does it not i.e. something that is not neccessarily true nor neccessarily false.

Don't know if I'm missing something here?
4. (Original post by bcrazy)
Is this not by definition impossible?
Not a tautology means not neccessarily true.
Not a contradiction means not neccessarily false.
Which by definition makes it a contingent does it not i.e. something that is not neccessarily true nor neccessarily false.

Don't know if I'm missing something here?
Same I am slightly confused, its in the exam paper.

"This statement is false!''
we know the statement is something that is either true or false, but we are told it's false, if the statement is true then its false if the statement is false and we are told it is false making it true... thus its neither true or false nor contingent.

I am sure tautology mean its a true and contradiction is false while contingent is a mixture.

http://www.cs.auckland.ac.nz/~chaitin/unm2.html
5. "This statement is false!''
Why is this a paradox? What does "false'' mean? Well, "false'' means "does not correspond to reality.'' This statement says that it is false. If that doesn't correspond to reality, it must mean that the statement is true, right? On the other hand, if the statement is true it means that what it says corresponds to reality. But what it says is that it is false. Therefore the statement must be false. So whether you assume that it's true or false, you must conclude the opposite! So this is the paradox of the liar.
6. I have a similar exam question, the only difference being:
"give an example of a statement about things in the world that can not be formalized as a contradiction nor a tautology nor a contingent proposition IN PROPOSITIONAL LOGIC.

I wonder if this possible or not?

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