In this manuscript, assuming that Graedel's 1991 results are correct (which implies that bounds on the solution values for optimization problems can be expressed in existential second order logic where the first order part is universal Horn), I will show that Clique and Vertex Cover can be solved in polynomial time if the input structure is ordered and contains a successor predicate. In the last section, we will argue about the validity of Graedel's 1991 results. Update: Manuscript withdrawn, because results are incorrect. If phi = phi_1 AND phi_2, and phi is a Horn formula, it does NOT mean that both phi_1 and phi_2 are Horn formulae. Furthermore, the cardinality constraint CANNOT be expressed as a universal Horn sentence in ESO (NOT even when the structure is ordered).
翻译:在本手稿中,假设格拉德尔1991年的结果是正确的(这意味着关于优化问题的解决方案值的界限可以用存在性第二顺序逻辑来表达,其中第一顺序部分为世界性非洲之角),我将表明,如果输入结构是定序的,并且包含一个后继的前提,则Clique和Vertex Cover 可以在多元时间内解决。在最后一节中,我们将争论格拉德尔1991年结果的有效性。更新:手稿被撤回,因为结果是不正确的。如果菲=phi_1和phi_2,以及菲是合角公式,它并不意味着菲1和菲2都是合角公式。此外,CANNOT在ESO(即使结构是定序的,CANNOT)中将主要限制表现为一个普遍的合角句。