# Tag Info

### Can anyone give me an instance of 3SAT with exactly one solution?

The empty 3SAT instance (over no variables) has one solution.

### What is wrong with this simple proof of P=NP?

The monotone version of X3SAT that your proof is based on has the nice property that setting a literal false in one clause will never cause the negation of that literal to be true in another, which ...
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### Reduction 3SAT and CLIQUE

Here is one possible way to reduce Clique to SAT (you can then further reduce it to 3SAT). This type of reduction is often used in (propositional) proof complexity, an area of complexity theory. ...
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### Can anyone give me an instance of 3SAT with exactly one solution?

One variable: $(A \lor A \lor A)$
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### Random restarts for unsatisfiable instances

There is some research in this area. In The Effect of Restarts on the Efficiency of Clause Learning Jinbo Huang shows empirically that restarts improve a solver's performance over suites of both ...
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### To prove 4-SAT CNF is NP-complete

In order to prove that 4-SAT is NP-complete, you need to prove that it is in NP and that it is NP-hard. Prove 4-SAT $\in$ NP Given an instance of 4-SAT and an answer that evaluates to TRUE, it's ...
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