Computability in Europe 2006
Logical Approaches to Computational Barriers
|Author(s):||Oleg Kudinov and Victor Selivanov|
|Slot:||Tue, 14:50-15:10, Faraday B (col. 2)|
We prove that the homomorphic quasiorder of finite k-labeled forests has undecidable elementary theory for k> 2, in contrast to the known decidability result for $k=2$. We establish also undecidablity (again for every $k\geq 3$) of elementary theories of two other relevant structures: the homomorphic quasiorder of finite k-labeled trees, and of finite k-labeled trees with a fixed label of the root element.
|websites: Arnold Beckmann||2006-06-23|