3SAT is the case where each clause has exactly 3 terms. EDIT (to include some information on the point of studying 3SAT): If someone gives you an assignment of values to the variables, it is very easy to check to see whether that assignment makes all the clauses true; in other words, you can efficiently check any alleged solution.

Jan 22, 2014 · For the pedantic's sake, we first have a polynomial reduction $3SAT \leq_p s3SAT$, where the later has strictly 3 terms per clause, not less (as accepted by the former). This is achieved by taking an instance of $3SAT$ and mapping the clauses respectively:

Aug 23, 2024 · $\begingroup$ The convention may differ. In the foundational paper of Karp, 3SAT is at most 3 literal per clause, but as Wikipedia note it, "Some authors restrict k-SAT to CNF formulas with exactly k literals.", and it shows how the …

Apr 13, 2017 · 3-SAT is NP-Complete because SAT is - any SAT formula can be rewritten as a conjunctive statement of literal clauses with 3 literals, and the satisifiability of the new statement will be identical to that of the original formula.

Dec 13, 2017 · Using this translation strategy, you can add a new linear constraint to the ILP for every clause in the 3SAT problem. The two problems are now equivalent: there's an integer solution to this ILP if and only if there's a boolean solution to the original 3SAT problem. An example instance of a 3SAT decision problem:

Jan 30, 2016 · Note: I've also asked this question on StackOverflow here. I've been reading this article which tries and explains how the max 2 sat problem is essentially a 3-sat problem and is NP-hard.

Sep 27, 2019 · Stack Exchange Network. Stack Exchange network consists of 183 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Mar 10, 2018 · I tried google and this site, but I couldn't find anything which explains why this method to solve $2SAT$ in polynomial time won't work for $3SAT$. I know it can't, otherwise $3SAT$ wouldn't be NP-Complete, but I'd like to understand why.

Feb 17, 2021 · Stack Exchange Network. Stack Exchange network consists of 183 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

That makes sense. Further reading showed me some sort of hint: Satisfying an instance of hornsat simultaneously with an instance of 2sat is np-complete. If I alter my method slightly, I get exactly a reduction from 3sat to hornsat+2sat. $\endgroup$ –