First-order definable problems for posets and reflexive graphs
Victor Dalmau, A Krokhin and B. Larose
In: LICS 04, 14-17 July 2004, Turku, Finland.
A retraction from a structure P to its substructure Q is a homomorphism from P onto Q that is the identity on Q. We present an algebraic condition which completely characterizes all posets and all reflexive graphs Q with the following poperty: the class of all posets or reflexive graphs, respectively, that admits a retraction onto Q is first-order definable.
|EPrint Type:||Conference or Workshop Item (Paper)|
|Project Keyword:||Project Keyword UNSPECIFIED|
|Subjects:||Theory & Algorithms|
|Deposited By:||Victor Dalmau|
|Deposited On:||29 November 2005|