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He took lessons in algebra from Augustus De Morgan , with a view to reading Pierre-Simon Laplace 's five volume work Mécanique Céleste ( Celestial Mechanics ) , by the age of fifty achieving his goal of sufficient mathematical knowledge to comprehend the scope of its methods .
 person: Augustus De Morgan; person: Pierre-Simon Laplace
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
 Entities: Augustus De Morgan, Pierre-Simon Laplace 
Answer:
 person: Augustus De Morgan; person: Pierre-Simon Laplace