Quantified conjunctive queries on partially ordered sets
نویسندگان
چکیده
منابع مشابه
Quantified Conjunctive Queries on Partially Ordered Sets
We study the computational problem of checking whether a quantified conjunctive query (a first-order sentence built using only conjunction as Boolean connective) is true in a finite poset (a reflexive, antisymmetric, and transitive directed graph). We prove that the problem is already NP-hard on a certain fixed poset, and investigate structural properties of posets yielding fixedparameter tract...
متن کاملTripled partially ordered sets
In this paper, we introduce tripled partially ordered sets and monotone functions on tripled partiallyordered sets. Some basic properties on these new dened sets are studied and some examples forclarifying are given.
متن کاملBlock-Sorted Quantified Conjunctive Queries
We study the complexity of model checking in quantified conjunctive logic, that is, the fragment of first-order logic where both quantifiers may be used, but conjunction is the only permitted connective. In particular, we study block-sorted queries, which we define to be prenex sentences in multi-sorted relational first-order logic where two variables having the same sort must appear in the sam...
متن کاملPartially Ordered Sets
For example, thus far, I had the fortune to work intimately with nine (9) undergraduate students on research questions in the areas of computational algebra and algebraic geometry. I am directing two master’s students in their research for their theses at Sam Houston State University. All of these undergraduate students have enrolled in graduate programs around the country. Three have finished ...
متن کاملHypergroupoids on Special Partially Ordered Sets
In recitals of this paper there we will be repeated the definitions and main results mentioned 1n [15] without proofs. The definition of the multioperation on partially ordered carrier set in this papers is idempotent, commutative but not associative operation. In the opening part of this article there we repeat fundamental definitions and some theorems without proofs. In the next part of this ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Theoretical Computer Science
سال: 2016
ISSN: 0304-3975
DOI: 10.1016/j.tcs.2016.01.010