Extension theory and its application

The articleExtension Set and Noncompatible Problems was published in 1983. It proclaimed the birth of extension theory. Its objects of study are contradictory problems in the realistic world; its theoretical pillars are matter element theory and extension set theory. Its basic methods are extension methods. Its practical methods are extension engineering methods, including the extension information method, extension system method and extension decision method, etc. Basic theory, practical method and application of extension theory in economy, management, control and artificial intelligence will be introduced.