Manuel Bodirsky - Cores of Countably Categorical Structures

lmcs:2224 - Logical Methods in Computer Science, January 25, 2007, Volume 3, Issue 1 - https://doi.org/10.2168/LMCS-3(1:2)2007
Cores of Countably Categorical StructuresArticle

Authors: Manuel Bodirsky ORCID

A relational structure is a core, if all its endomorphisms are embeddings.
This notion is important for computational complexity classification of constraint satisfaction problems. It is a fundamental fact that every finite structure has a core, i.e., has an endomorphism such that the structure induced by its image is a core; moreover, the core is unique up to isomorphism. Weprove that every \omega -categorical structure has a core. Moreover, every \omega-categorical structure is homomorphically equivalent to a model-complete core, which is unique up to isomorphism, and which is finite or \omega
-categorical. We discuss consequences for constraint satisfaction with \omega
-categorical templates.


Volume: Volume 3, Issue 1
Published on: January 25, 2007
Imported on: September 23, 2005
Keywords: Computer Science - Logic in Computer Science, F.4.1

35 Documents citing this article

Consultation statistics

This page has been seen 3195 times.
This article's PDF has been downloaded 557 times.