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Moreover , our study reveals that the topology optimization formulation generally leads to self-supporting designs without extraneous self-supporting constraints .
 engineering feature: topology optimization; engineering feature: self-supporting designs; engineering feature: self-supporting
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: manufacturing standard, machanical property, manufacturing process, material, engineering feature, process parameter, machine or equipment, application, process characterization, enabling technology, biomedical, concept or principle 
Text: {0} 
 Entities: topology optimization, self-supporting designs, self-supporting 
Answer:
 engineering feature: topology optimization; engineering feature: self-supporting designs; engineering feature: self-supporting