ExpTime Tableaux for the Description Logic SHIQ Based on Global State   Caching and Integer Linear Feasibility Checking
  We give the first ExpTime (complexity-optimal) tableau decision procedure for checking satisfiability of a knowledge base in the description logic SHIQ when numbers are coded in unary. Our procedure is based on global state caching and integer linear feasibility checking. 
Linh Anh Nguyen
cs.LO