
Nowadays, it is widely recognized that rough sets applications have a great importance in several fields, such as granular computing, data mining and approximate reasoning. This is witnessed by the increasing number of papers and conferences about rough sets and by the implementation of reallife applications based on rough sets.
This fact leads to a continuous and useful development of applicative aspects of rough sets methodologies. Even though this attention to application is of great importance, it is not excluded that theoretical aspects concerning with foundations of rough sets, both logical and mathematical, must be taken into account.
To present the stateoftheart scientific results and to start a fruitful discussion about rough sets from the theoretical standpoint, the first workshop on rough sets theory will be held in Milano, Italy, May 2527, 2009 following the special sessions on Rough sets foundations organized at JRS07 and RSKT08. Great importance will be dedicated to discussion and included in the workshop there will be a round table about foundational and open problems in rough sets theory.
The topics of main interest (but not limited to) are:
 Algebraic structures in rough set theory
 Rough Logics
 Topological and modal approach to roughness
 Granular information systems
 Rough mereology
 Generalization of rough set theory: near sets and nearness approximation spaces
 Category theoretic and philosophical aspects of rough set theory
 Theoretical aspects of rough entropies
 Complexity of rough setrelated optimization/decision problems
 Relationship with other paradigms (formal concept analysis, fuzzy sets, Atanassov's IFS,...)
 Rough sets in approximate reasoning (judgment) in distributed environments (e.g., in multiagent systems) including rough sets and interactive computations
 Rough sets in reasoning about changes
 Rough sets in approximate reasoning in dialog of systems with human experts
 Rough sets and ontology approximation
 Rough sets and natural language understanding
