Journal of Logic and Computation Advance Access published online on May 4, 2009
Journal of Logic and Computation, doi:10.1093/logcom/exp027
Original Papers |
Linear Temporal Logic 

K extended by Multi-Agent Logic Kn with Interacting Agents
Department of Computing and Mathematics, Manchester Metropolitan University, Manchester M1 5GD, UK and Siberian Federal University, Krasnoyarsk, Russia.
E-mail: v.rybakov{at}mmu.ac.uk
Received 13 June 2008.
| Abstract |
|---|
We study an extension 

K of the linear temporal logic 

K by implementing multi-agent knowledge logic KD45m (which is often referred as multi-modal logic S5m). The temporal language of our logic adapts the operations U (until) and N (next) and uses new temporal operations: Uw—weak until, and Us—strong until. We also employ the standard agents knowledge operations Ki from the multi-agent logic KD45m and extend them with an operation IntK responsible for knowledge obtained via interaction of agents. The semantic models for 

K are Kripke/Hintikka-like structures
C based on the linear time. Structures
C use i
N as indexes for time, and the base set of any
C consists of clusters C(i) (for all i
N) containing all possible states at the time i. Agents knowledge is modelled in time clusters C(i) via agents knowledge accessibility relations Rj. The logic 

K is the set of all formulas which are valid (true) in all such models
C w.r.t. all possible valuations. We prove that 

K is decidable: we reduce the decidability problem to verification of validity for special normal reduced forms of rules in specific models (not 

K models) of size single-exponential in size of the rules. Furthermore, we extend these results to a linear temporal logic 

K(Z) based on the time flow indexed by all integer numbers (with additional operations Since and Previous). Also we show that 

K has the finite model property (fmp) while 

K (Z) has no standard fmp.
Keywords: Linear temporal logic; modal logics multi-agent logic; interacting agents; decidability; algorithms; inference rules