Questions tagged [resolution]

The tag has no usage guidance.

6
votes
1answer
86 views

Axioms of Minimum Size Resolution Refutations

Let $\phi$ be an unsatisfiable CNF formula and let $\Pi$ be a resolution refutation of $\phi$ of minimum size. Let $\psi$ be the subformula of $\phi$ containing the clauses that actually appear as ...
9
votes
0answers
127 views

Direct Proof that the Pigeonhole Principle is Hard for Regular Resolution

It is well known that the pigeonhole principle $PHP_n^{n+1}$ is hard for general resolution. The original proof due to Haken is elegant. One first defines a complexity measure for derived clauses, in ...
6
votes
1answer
192 views

Resolution vs Nondeterministic Search Problems

It is well known that each resolution refutation $\Pi$ for an unsatisfiable CNF formula $F = C_1\wedge C_2 \wedge ... \wedge C_m$ over variables $X$ can be translated in polynomial time (in the size ...
4
votes
1answer
148 views

resolution based theorem prover for temporal logic

I am looking at implementing a a resolution-based theorem prover for propositional linear temporal logic (PLTL) (as opposed to a model checker). The ones out there (by Fisher et. al. and others) are ...
5
votes
1answer
222 views

Mechanization of Mathematics

Its been a while since I took my theory course, but I recall that Hilberts Decision problem was shown to be false. By the completeness theorem of first-order logic, a statement is universally valid ...
3
votes
0answers
55 views

Substitution in Resolution Proofs

Let $F = C_1 \wedge C_2\; \wedge ... \wedge\; C_m$ be a unsatisfiable $k$-CNF on variables $x_1,...,x_n$, where $k$ is constant. Let $x_j\rightarrow x_j^1\wedge x_j^2$ be a substitution that replaces ...
-4
votes
1answer
354 views

“tree-like” vs “DAG-like” resolution

hi all there seems to be a deep/not-much-explored phenomenon in the way that SAT resolution proofs can define a tree and/or a DAG & its relationship to lower bounds/circuit complexity. could there ...
2
votes
0answers
179 views

Most general form of SAT which is in P

2-SAT is in P. Additionally, a (CNF) SAT-problem is trivially poly-time solvable if no two expressions can be resolved (via Robinson resolution, ie for every pair of disjunctive clauses, they either ...
1
vote
1answer
235 views

What is resolution ((in FOL))? [closed]

I'm searching for an authoritative definition of resolution (logic resolution). Preferably on a reference freely available on the Internet (so I can read it right now). If this is too broad then ...
1
vote
1answer
113 views

Implied Clause and Resolvent

(I posted this question on MathSE first, no answer, that is the reason why I come here.) Let $F$ be a 3-CNF formula on $n$ variables. A clause $c$ is implied by the formula if $F$ and $F \wedge c$ ...
4
votes
1answer
186 views

About Closure under Resolution

The question looks very simple, that is why I posted it first on MathSE, unsuccesfully - no answer for 12 days. I tried to find a short and elegant answer to the question, but I haven't succeed yet. ...
15
votes
2answers
2k views

Is propositional resolution a complete proof system?

This question is about propositional logic and all occurrences of "resolution" should be read as "propositional resolution". This question is something extremely basic but it has been bothering me ...