Gradual forgetting operator in intuitionistic statement networks

The investigated intuitionistic statement networks facilitate designing and development of complex expert systems. Within these networks, statements consist of contents and values. Statement values are based on a concept introduced in intuitionistic fuzzy sets, i.e. they contain independent belief about validity and nonvalidity of information presented by statement contents. The relationships between statements are modeled in the form of a set of necessary as well as sufficient conditions, and these conditions are considered as corresponding inequalities between statement values. The paper introduces gradual forgetting operator of statement values. The networks with such an operator may be used as models of dynamic objects. They allow for non-monotonic reasoning required for monitoring and diagnostic systems.