Sciweavers

LICS
2010
IEEE
13 years 10 months ago
Fixed-Point Definability and Polynomial Time on Graphs with Excluded Minors
We prove that fixed-point logic with counting captures polynomial time on all classes of graphs with excluded minors. That is, for every class C of graphs such that some graph H is...
Martin Grohe
ECCC
2010
82views more  ECCC 2010»
14 years 11 days ago
On optimal proof systems and logics for PTIME
We prove that TAUT has a p-optimal proof system if and only if a logic related to least fixed-point logic captures polynomial time on all finite structures. Furthermore, we show t...
Yijia Chen, Jörg Flum
BIRTHDAY
2010
Springer
14 years 1 months ago
Fixed-Point Definability and Polynomial Time on Chordal Graphs and Line Graphs
The question of whether there is a logic that captures polynomial time was formulated by Yuri Gurevich in 1988. It is still wide open and regarded as one of the main open problems...
Martin Grohe