Based on the polytomous generalization of knowledge space theory,the concept of polyto-mous S-approximation spaces is proposed.After that,the properties of upper and lower approxima-tions under different operations and decision mappings are investigated.Moreover,the concept of up-per and lower approximation polytomous knowledge states is introduced,and the conditions under which the family of upper and lower approximation polytomous knowledge state sets can form poly-tomous knowledge structures are explored.In particular,the conditions of the polytomous knowl-edge structure to satisfy intersection and union closure are discussed.Polytomous S-approximation spaces provide a new research approach and method for the construction and application of polyto-mous knowledge structures,and the results obtained will enrich and develop the S-approximation spaces theory and knowledge space theory.
维普
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