JOURNAL OF APPLIED LOGICS-IFCOLOG JOURNAL OF LOGICS AND THEIR APPLICATIONS
|
2018年
/
5卷
/
08期
基金:
奥地利科学基金会;
关键词:
constraint satisfaction;
random partial order;
homogeneous structures;
model theory;
polymorphism clones;
D O I:
暂无
中图分类号:
B81 [逻辑学(论理学)];
学科分类号:
010104 ;
010105 ;
摘要:
In this paper we determine the complexity of a broad class of problems that extend the temporal constraint satisfaction problems classified by Bodirsky and Kara. To be more precise, we study problems Poset-SAT(Phi) where Phi is a given set of quantifier-free <=-formulas. An instance of Poset-SAT(Phi) then consists of finitely many variables and constraints on them expressible in Phi; the question is then whether this input can be satisfied in some partial order or not. We show that every such problem is either NP-complete or in P, depending on the constraint language Phi. All Poset-SAT problems can be formalized as constraint satisfaction problems of reducts of the random partial order. We use model-theoretic concepts and techniques from universal algebra to study these reducts. In the course of this analysis we establish a dichotomy that we believe is of independent interest in universal algebra and model theory.