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Topic: Emil Post

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In the News (Thu 25 Apr 19)

  Emil Leon Post Information
Emil Leon Post (February 11 1897 – April 21 1954) was an American mathematician and logician.
His Post correspondence problem contributed to the decision problems of recursion theory, as a new model of computation.
Emil Leon Post at the MacTutor History of Mathematics archive.
www.bookrags.com /wiki/Emil_Leon_Post   (277 words)

 Post biography
Post's early death at the age of 57 was almost certainly a direct consequence of the treatment he received for his mental illness.
Post received the electric shock treatment on a number of occasions and it was while he was in a mental institution, shortly after receiving electric shocks, that he suffered a heart attack and died.
Post is best known for his work on polyadic groups, recursively enumerable sets, and degrees of unsolvability, as well as for his contribution to the unsolvability of problems in combinatorial mathematics.
www-history.mcs.st-andrews.ac.uk /Biographies/Post.html   (1953 words)

 BIALYSTOK UNIV. PL * MATHESIS UNIVERSALIS, No.7, 1998 * W.Marciszewski: Post's Problem of Creativity
Post contributed to grasping the essence of finitary mechanical operations on equal footing with Turing and Hilbert.
Emil Post's concern with what we nowadays call cognitive science was greater than it can be judged when one reads his published metamathematical results.
Post notices that in the mental process of proof creative and non-creative parts are intermingled (p.433).
www.calculemus.org /MathUniversalis/7/09marci.html   (3126 words)

 Post canonical system - Esolang
A Post canonical system is a formalism for modelling logical theories, developed by Emil Post in the 1930's.
Post canonical systems have been shown to be in the same computational class as Turing machines, that is, they are Turing-complete.
Post normal systems, for example, can only have one "wildcard" in each production - at the end of the antecedent and the beginning of the consequent.
esoteric.voxelperfect.net /wiki/Post_canonical_system   (253 words)

 Emil Leon Post Papers, American Philosophical Society
Emil L. Post was born in Poland in 1897.
Post was able to show that the axioms of propositional calculus were both complete and consistent with respect to the truth table method.
The remaining Post Papers were donated to the APS by Phyllis Post Goodman in 1992 (Accession 1992-1345ms and 1992-1088ms) and 1994 (Accession 1994-99ms, 1994-367ms, and 1994-238ms).
www.amphilsoc.org /library/mole/p/post.htm   (1636 words)

 Swiss Post - Emil designs a special stamp on the subject of humour
Swiss Post's wish was to focus on Emil Steinberger as an artist rather than reproduce a picture of him.
Emil Steinberger is immortalized as the stamp's designer, as his name appears in the margin.
Swiss Post is supplying a souvenir booklet along with the stamp, in which the newly appointed stamp designer explains how the stamp evolved and propounds his views on "humour".
www.post.ch /EN/index/uk_mm04_marke_emil.htm?viewId=716   (504 words)

 Post-Turing machine Information
Turing's paper was received for publication in May of 1936, followed by Post's in October.) A Post-Turing machine uses a binary alphabet, an infinite sequence of binary storage locations, and a primitive programming language with instructions for bi-directional movement among the storage locations and alteration of their contents one at a time.
Post's model employs a "symbol space" consisting of a "two-way infinite sequence of spaces or boxes", each box capable of being in either of two possible conditions, namely "marked" (as by a single vertical stroke) and "unmarked" (empty).
Martin Davis was a undergraduate student of Emil Post's (cf Davis in Steen, p.
www.bookrags.com /wiki/Post-Turing_machine   (1098 words)

 Post   (Site not responding. Last check: 2007-10-20)
Emil Post's family moved to the USA when he was seven years old and, from that time, he lived in USA.
Post showed that the word problem for semigroups was recursively insoluble in 1947, giving the solution to a problem posed by Thue in 1914.
Subsequent work by Post was instrumental to the further progress of the theory of recursive functions.
homepages.compuserve.de /thweidenfeller/mathematiker/Post.htm   (552 words)

 Emil Leon Post
Emil Leon Post (February 11 1897 - April 21 1954) was a Polish-American mathematician and logican.
He was born in a Jewish family in Augustow, and died New York City, USA.
Emil Leon Post introduced the Post machine in 1936, an abstract computer, independently of the Turing machine.
www.teachersparadise.com /ency/en/wikipedia/e/em/emil_leon_post.html   (106 words)

 Amazon.com: Emil Post: Collected Papers (Contemporary Mathematicians): Books: M. Davis   (Site not responding. Last check: 2007-10-20)
Emil Post was a pioneer of twentieth century mathematical logic whose influence on what has come to be called computer science is particularly remarkable considering his lack of any contact with computing machines.
Although his initial contributions were to mathematical analysis, Post was caught up in the excitement generated by the publication of Principia Mathematica purporting to demonstrate that all of mathematics could and should be regarded as a branch of logic.
Post's later work included the first example of the unsolvability of a mathematical problem that had not originally arisen in the field of logic as well as the founding of the modern theory of recursively enumerable sets and of the theory of degrees if unsolvability.
www.amazon.com /Emil-Post-Collected-Contemporary-Mathematicians/dp/0817635793   (719 words)

 Algorithm at AllExperts
Emil Post (1936) described the actions of a "computer" (a man) as follows: :"...two concepts are involved: that of a symbol space in which the work leading from problem to answer is to be carried out, and a fixed unalterable set of directions.
Turing begins, as did Post, with an analysis of a human computer that he whittles down to a simple set of basic motions and "states of mind".
Post defines a simple algorithmic-like process of a man writing marks or erasing marks and going from box to box and eventually halting, as he follows a list of simple instructions.
en.allexperts.com /e/a/al/algorithm.htm   (5672 words)

 Inconsistent Logic Systems
Emil Post was one that took the consistency problem as being that you could prove false statements.
And for his work he proposed the definition of consistency that a logical system was consistent if it could not prove a single propositional letter as a theorem ("p", for example).
Hilbert, in a manner similar to Post, said that a system was consistent if there is a selected wff that is not a theorem of the system.
www.cc.utah.edu /~nahaj/logic/structures/systems/inconsistent.html   (584 words)

 The Limitations of Machines And Men as Problem-Solvers   (Site not responding. Last check: 2007-10-20)
According to Post, this is equivalent to deciding whether an integer is a member of what Post calls a creative set.
At first sight this seems to suggest that Emil Post was more intelligent than any possible machine, although Post himself modestly refrained from drawing this conclusion.
Namely, Post's improvement procedure is itself mechanical and can be carried out by machine, so that the machine can improve its own procedure or can even improve Post, if given a description of Post's own methods of trying to decide sentences of the lower predicate calculus.
www-formal.stanford.edu /pub/jmc/towards/node14.html   (1054 words)

 Asia Observer - web directory and search
Post, Emil L. Post Manuscript Guide - Notes on papers and correspondence by Post at the American Philosophical Society.
Emil Post - Biography of Emil Leon Post (1897-1954).
Post's Problem of Creativity - An essay discussing some of Post's philosophical ideas in a biographic setting.
www.asiaobserver.com /cgi-local/anacondaodpp.pl?passurl=/Science/Math/Logic_and_Foundations/History/People/Post,_Emil_L.   (156 words)

 Mathematics Magazine:February 2004
Emil Post and His Anticipation of Gödel and Turing
Emil Post was one of the great mathematical logicians of the 20th century, the discoverer of several results generally credited to Gödel and Turing.
This article outlines Post's life and career, explains his distinctive approach to the famous incompleteness and unsolvability theorems, and compares it with the approaches of Gödel and Turing.
www.maa.org /pubs/mag_feb04_toc.html   (786 words)

 Historical Notes: History [of undecidability]
Alonzo Church gave the first explicit example of an undecidable problem in 1935 when he showed that no finite procedure in lambda calculus could guarantee to determine the equivalence of two lambda expressions.
Some similar issues had already been considered by Emil Post in the context of tag and multiway systems starting in the 1920s, and in 1947 Post and Andrei Markov were able to establish that an existing mathematical question - the word problem for semigroups (see page 1147) - was undecidable.
By the 1960s undecidability was being found in all sorts of systems, but most of the examples were too complicated to seem of much relevance in practical mathematics or computing.
www.wolframscience.com /reference/notes/1136d   (272 words)

 Volume 2(15), 1998: Emil L. Post and the Problem of Mechanical Provability
Post and the development of mathematical logic and recursion theory.
On the development of Emil Post's ideas in structural complexity theory.
The Post correspondence problem as a tool for proving undecidability in logics of probabilistic programs.
logika.uwb.edu.pl /studies/vol2.htm   (110 words)

 Chapters 20-22 Highlights
Recall that Emil Post developed a machine for doing computations at the same time that Turing developed the Turing machine.
It is interesting to find out how Post's machine works and to learn that the two models are equivalent in computational power.
We will not go through the details of the proof but it is similar to the previous proof in which the author proves that a Post machine is equivalent to a Turing machine.
www.mathsci.appstate.edu /~dap/classes/2490/chap20-22.html   (861 words)

Although written while he was an undergraduate, Post did not submit the paper to the American Mathematical Society until 1923 and it was not finally published until 1930.
Gödel published his Incompleteness Theorems in 1931, Post realised that he had waited too long to publish what he had proved and that now the whole credit would go to
In 1936 he proposed what is now known as a Post machine, a kind of automaton which predates the notion of a program which
www.educ.fc.ul.pt /icm/icm2003/icm14/Post.htm   (1847 words)

 Atlas: Closing the circle: Emil Post's approach to undecidability by Liesbeth De Mol   (Site not responding. Last check: 2007-10-20)
It is by now an accepted fact that Emil Leon Post anticipated the incompleteness and undecidability results of Gödel, Church and Turing in the period from 1920-21 during his stay at the Princeton University as a Proctor fellow.
His failure `to be the first' though seems not to have discouraged him: In the forties he wrote his important paper on recursion theory, his proof of the unsolvability of the Correspondence Problem, and furthermore he proved the unsolvability of the word problem for semi-groups.
When Post finally tried to publish his early results in the paper Absolutely Unsolvable Problems and Relatively Undecidable Propositions - Account of an Anticipation, he was well aware of the fact that Gödel, Turing and Church had already published similar results in the thirties.
atlas-conferences.com /cgi-bin/abstract/caqb-09   (457 words)

 Chapter 19 Turing Machines
A different model was introduced by Emil Post in that year.
Post's model used a queue as a data structure.
Since then both Turing's and Post's computational models have been shown to be equivalent in power.
www.mathsci.appstate.edu /~dap/classes/2490/chap19.html   (1729 words)

 About Emil Steiner - Offbeat
Emil Steiner started his writing career as an investigative reporter in Prague, covering the fleecing of tourists by taxis and hotels.
August 11, 2006 08:23 AM Emil, there is a thumbnail of you looking all serious...like a real columnist!
September 14, 2006 01:52 PM emil, thanks for the zombie coverage.
blog.washingtonpost.com /offbeat/2005/06/about_emil_steiner.html   (146 words)

 Math Forum Discussions
Replies: 5 Last Post: Jun 6, 2004 12:11 PM
I Grattan-Guinness, The manuscripts of Emil L Post,
Post, E.L. 'Finite Combinatory Processes - Formulation 1'.
mathforum.org /kb/thread.jspa?messageID=408025&tstart=0   (122 words)

 Tana's Habitat - Emil Post - Forum Decorum   (Site not responding. Last check: 2007-10-20)
Make sure that you post your question or comment (just once to avoid verbal clutter) in the correct place.
Try to be succinct and descriptive with the title, so that your neighbors will know immediately if the post pertains to them.
Use of capital letters and excessive punctuation in subject headings is considered "shouting" and is generally frowned upon.
www.tanashabitat.com /emilpost/0311052of5.asp   (152 words)

 Closing the circle: an analysis of Emil Post’s early work , Liesbeth De Mol
However, already in 1921 the young logician Emil Post worked on similar problems which resulted in what he called an “anticipation” of these results.
This failure ‘to be the first’, did not discourage him: his contributions to mathematical logic and its foundations should not be underestimated.
It is the purpose of this article to show that an interest in the early work of Emil Post should be motivated not only by this historical fact, but also by the fact that Post’s approach and method differs substantially from those offered by Gödel, Turing and Church.
projecteuclid.org /Dienst/UI/1.0/Display/euclid.bsl/1146620062?abstract=   (264 words)

 Learn more about Emil Leon Post in the online encyclopedia.   (Site not responding. Last check: 2007-10-20)
Learn more about Emil Leon Post in the online encyclopedia.
Enter a phrase or search word in the box below.
Hint: Play with putting spaces before and after your words to see the different results you get.
www.onlineencyclopedia.org /e/em/emil_leon_post.html   (167 words)

 erik’s weblog » Blog Archive » ExplorerCanvas
Over the last few months, me, Glen and Emil have been working on an open source version of canvas for Internet Explorer.
The canvas elements are recreated when initialized so do not store a reference to them before they are actually used.
This entry was posted on Tuesday, March 28th, 2006 at 12:05 and is filed under Web, JavaScript, Internet Explorer, DHTML, Google.
erik.eae.net /archives/2006/03/28/12.05.59   (653 words)

 Post machine
Note: Similar to a Turing machine, but uses a queue instead of an infinite tape.
Post, E. Finite Combinatory Processes - Formulation 1, Journal of Symbolic Logic, 1, 103-105, 1936.
"Post machine", in Dictionary of Algorithms and Data Structures [online], Paul E. Black, ed., U.S. National Institute of Standards and Technology.
www.nist.gov /dads/HTML/postMachine.html   (94 words)

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