Henry Ouellette 4/16/2020 COG356 Emil Post: A Biography Prof. Craig Graci

“I study Mathematics as a product of the human mind and not as absolute” - Emil Leon Post Emil Leon Post was born in the Russian Empire before it was Poland. Post was born on February 11th, 1897 in Augustow, Suwałki Governorate, Congress Poland, Russian Empire. Post was born into a Polish-Jewish family. In 1904, Post, along with his family emigrated from now Poland to New York City, where his uncle and father worked in the fur trade. Post’s early life can be described by speed bumps in the road. When Post was approximately 12 years old, he lost his left arm in a car accident. This was detrimental to Post, as he wanted to become an astronomer when he grew older. Since you kind of need both hands to be able to turn a telescope, he ruled that out as a possible profession. Instead, Post focused more on mathematics, an area he already excelled in. Post flew through the Townsend Harris High School, where it is presumed, he graduated. Post continued onto the City College of New York, where he graduated in 1917. Post had been working on an incredibly influential paper during his time at the City College of New York, and it is rumored that he had finished his bombshell of a paper before he had even graduated from undergraduate college. He didn’t publish the paper until 1930, however, as he believed his sources needed to be researched further. Post graduated from the City College with a Master’s in Mathematics. He would continue to Columbia University, where he would obtain his Doctorate in Mathematics. Post would then go on to teach high school mathematics for a few years, but would find his home at the City College where he graduated. Post was the first person to prove that the Propositional Calculus was complete. This marked the beginning of his career in computability theory. Post used truth tables to prove his points, and he came to the conclusion that a formula is well-formed and provable if we add any not well-formed formula to the axioms. Post was a pioneer of computability and computer science, which is interesting, as he never touched a computer. His Post Production Systems are massively influential to the computer science field of knowledge, as they can produce an output algorithmically without help from a computer. Post’s Problem is very similar to Alan Turing’s Halting Problem, with the only difference being in the Turing Degree of the set in question. The Henry Ouellette 4/16/2020 COG356 Emil Post: A Biography Prof. Craig Graci problem states that there exists an incomputable recursively enumerable set. This problem was solved in the 50s by the priority method in recursion theory.

Works Cited

• Bio and Quote - https://prabook.com/web/emil.post/1121175 • Image https://en.wikipedia.org/wiki/Emil_Leon_Post