First-Order Definable Retraction Problems for Posets and Reflexive Graphs
Presentation / Conference Contribution
Dalmau, V., Krokhin, A., & Larose, B. (2023, July). First-Order Definable Retraction Problems for Posets and Reflexive Graphs. Presented at 19th Annual IEEE Symposium on Logic in Computer Science (LICS'04), 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 characterises all posets and all reflexive graphs Q with the following property: the c... Read More about First-Order Definable Retraction Problems for Posets and Reflexive Graphs.