“…Shi 4 obtained P-sets by introducing dynamic characteristics into Cantor set and improving . Cantor set is given, and is attribute set of , the concepts and characteristics of P-sets are as follows: - Supplementing some attributes in , then becomes , ; becomes internal P-sets , ;
- Deleting some attributes in , then becomes , ; becomes outer P-sets , ;
- If attributes are supplemented and deleted in at the same time, becomes and , where ; becomes internal P-sets and outer P-sets , where ; or becomes , is the P-sets generated by .
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