arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 0707.4255cs.CCcs.LO
收藏

Promise下命题证明的复杂性

Complexity of Propositional Proofs under a Promise

Nachum Dershowitz, Iddo Tzameret

摘要:

我们研究-命题证明复杂性的框架内-CNF公式的承诺下,任何可满足的公式有许多令人满意的任务,其中“许多”代表一个明确指定的函数$\Lam$的变量$n$的证明不可满足的问题。为此,我们开发命题证明系统下不同的措施的承诺(即不同的$\Lam$)作为扩展的决议。这是通过增加公理的分辨率来实现的,这些公理大致可以消除布尔电路定义的真值分配集。然后,我们研究了这样的系统的复杂性,在平均情况下,在不同大小的承诺下,分辨率之间的指数分离:1。对于任何常数$0<\eps<1$,当承诺为$\eps\cd2^n$时,对于所有不可满足的3CNF公式,归结具有多项式大小的反驳。2.对于任意常数$0<δ<1$,当promise为$2^{δn}$(子句数为$o(n^{3/2})$)时,随机3CNF公式没有次指数大小分辨率反驳。

英文摘要:

We study -- within the framework of propositional proof complexity -- the problem of certifying unsatisfiability of CNF formulas under the promise that any satisfiable formula has many satisfying assignments, where ``many'' stands for an explicitly specified function $\Lam$ in the number of variables $n$. To this end, we develop propositional proof systems under different measures of promises (that is, different $\Lam$) as extensions of resolution. This is done by augmenting resolution with axioms that, roughly, can eliminate sets of truth assignments defined by Boolean circuits. We then investigate the complexity of such systems, obtaining an exponential separation in the average-case between resolution under different size promises: 1. Resolution has polynomial-size refutations for all unsatisfiable 3CNF formulas when the promise is $\eps\cd2^n$, for any constant $0<\eps<1$. 2. There are no sub-exponential size resolution refutations for random 3CNF formulas, when the promise is $2^{δn}$ (and the number of clauses is $o(n^{3/2})$), for any constant $0<δ<1$.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑