Questions tagged [proof-complexity]

propositional proof systems and corresponding bounded arithmetic theories

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8
votes
2answers
427 views

Postselection in geometric complexity theory

Context: As I understand, in geometric complexity theory, the existence of obstructions serves as a proof-certificate, so to speak, for the nonexistence of an efficient computational circuit for the ...
7
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0answers
183 views

Oracle sparating FIP for bounded-depth Frege from FIP for Frege (and hardness conditions on DDH)

Is there an oracle such that in the relativized world, bd-Frege (bounded depth Frege propositional proof system) has FIP (feasible interpolation property) but Frege does not have FIP? Such an oracle ...
13
votes
2answers
523 views

Does coNP-complete problem have subexponential size certificate?

Assuming NP != coNP, then there is no polynomial size certificate for coNP-complete problem. But what about subexponential size certificate? Particularly for coSAT, is there subexponential size proof ...
38
votes
2answers
4k views

Axioms necessary for theoretical computer science

This question is inspired by a similar question about applied mathematics on mathoverflow, and that nagging thought that important questions of TCS such as P vs. NP might be independent of ZFC (or ...
15
votes
3answers
596 views

Theories which characterize classes of computational complexity

When reading the paper "An applicative theory for FPH" you can encounter the following passage: Considering theories which characterize classes of computational complexity, there are three ...
11
votes
1answer
710 views

NP vs co-NP and second-order logic

Assume that NP=co-NP and polynomial $p(x)$ bounds the length of the proof of unsatisfiability for a 3-CNF instance $x$. Then are there any results on what form any proof of unsatisfiability for $x$ of ...
10
votes
1answer
244 views

A direct sum theorem for Resolution clause space complexity?

Resolution is a scheme to prove unsatisfiability of CNFs. A proof in resolution is a logical deduction of the empty clause for the initial clauses in of the CNF. In particular any initial clause can ...
36
votes
2answers
2k views

If P=NP, could we obtain proofs of Goldbach's Conjecture etc.?

This is a naive question, out of my expertise; apologies in advance. Goldbach's Conjecture and many other unsolved questions in mathematics can be written as short formulas in predicate calculus. For ...
14
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0answers
269 views

Any example of an unsatisfiable integer program with non constant Rank Lower bounds for LS+ cuts but with short LS+ refutations?

Assume we want to refute an unsatisfiable CNF. We can interpret it as an integer program, thus a refutation can be done by applying Lovasz-Schrijver semidefinite cuts ($LS_{+}$ cuts) to its linear ...
11
votes
1answer
648 views

Using Kolmogorov complexity to establish proof complexity lower bounds?

The motivation for this question is the fact that most n-bit strings are incompressible. Intuitively, we can propose by analogy that most proofs for Tautologies are incompressible to polynomial size. ...
8
votes
2answers
889 views

PCP theorem and proof complexity?

It is known that if $P=NP$ then $CoNP= PCP[O(log(n)),O(1)]$. Also, it is known that $NEXP=PCP[poly(n),poly(n)]$. It appears that PCP can't tell us which natural problems are not in $NP$. I wonder if ...
19
votes
3answers
929 views

What algorithms are known for computing Craig interpolants?

Is there any survey of algorithms for computing interpolants? What about papers on only one algorithm? The case I'm most interested in is $A=\lnot p\land q$ and $C=q$, plus the constraint that the ...
28
votes
6answers
1k views

Well known classes of boolean formulas that require exponentially long resolution proofs

You might often find cutting plane methods, variable propagation, branch and bound, clause learning, intelligent backtracking or even handwoven human heuristics in SAT solvers. Yet for decades the ...

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