A universal-algebraic proof of the complexity dichotomy for Monotone Monadic SNP
M Bodirsky, F Madelaine, A Mottet - … of the 33rd Annual ACM/IEEE …, 2018 - dl.acm.org
The logic MMSNP is a restricted fragment of existential second-order logic which allows to
express many interesting queries in graph theory and finite model theory. The logic was …
express many interesting queries in graph theory and finite model theory. The logic was …
A proof of the algebraic tractability conjecture for monotone monadic SNP
M Bodirsky, F Madelaine, A Mottet - SIAM journal on computing, 2021 - SIAM
The logic MMSNP is a restricted fragment of existential second-order logic which can
express many interesting queries in graph theory and finite model theory. The logic was …
express many interesting queries in graph theory and finite model theory. The logic was …
Knowledge graphs: Research directions
A Hogan - Reasoning Web. Declarative Artificial Intelligence: 16th …, 2020 - Springer
In these lecture notes, we provide an overview of some of the high-level research directions
and open questions relating to knowledge graphs. We discuss six high-level concepts …
and open questions relating to knowledge graphs. We discuss six high-level concepts …
The data complexity of ontology-mediated queries with closed predicates
In the context of ontology-mediated querying with description logics (DLs), we study the data
complexity of queries in which selected predicates can be closed (OMQCs). We provide a …
complexity of queries in which selected predicates can be closed (OMQCs). We provide a …
[PDF][PDF] A dichotomy for first-order reducts of unary structures
M Bodirsky, A Mottet - Logical Methods in Computer Science, 2018 - lmcs.episciences.org
Many natural decision problems can be formulated as constraint satisfaction problems for
reducts A of finitely bounded homogeneous structures. This class of problems is a large …
reducts A of finitely bounded homogeneous structures. This class of problems is a large …
Dichotomies in ontology-mediated querying with the guarded fragment
We study ontology-mediated querying in the case where ontologies are formulated in the
guarded fragment of first-order logic (GF) or extensions thereof with counting and where the …
guarded fragment of first-order logic (GF) or extensions thereof with counting and where the …
[PDF][PDF] Ontology-Mediated Querying with the Description Logic EL: Trichotomy and Linear Datalog Rewritability.
C Lutz, L Sabellek - IJCAI, 2017 - informatik.uni-leipzig.de
We consider ontology-mediated queries (OMQs) based on an EL ontology and an atomic
query (AQ), provide an ultimately fine-grained analysis of data complexity and study …
query (AQ), provide an ultimately fine-grained analysis of data complexity and study …
Deciding FO-rewritability of regular languages and ontology-mediated queries in linear temporal logic
Our concern is the problem of determining the data complexity of answering an ontology-
mediated query (OMQ) formulated in linear temporal logic LTL over (Z,<) and deciding …
mediated query (OMQ) formulated in linear temporal logic LTL over (Z,<) and deciding …
Smooth approximations and relational width collapses
We prove that relational structures admitting specific polymorphisms (namely, canonical
pseudo-WNU operations of all arities n≥ 3) have low relational width. This implies a …
pseudo-WNU operations of all arities n≥ 3) have low relational width. This implies a …
The data complexity of description logic ontologies
We analyze the data complexity of ontology-mediated querying where the ontologies are
formulated in a description logic (DL) of the ALC family and queries are conjunctive queries …
formulated in a description logic (DL) of the ALC family and queries are conjunctive queries …