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# James Propp

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## Registered User

 Name James Propp Member for 3 years Seen 2 days ago Website Location Age
 Jun14 comment Sperner’s lemma and Tucker’s lemma@domotorp: Thanks for pointing out this article! It was very relevant and interesting. Jun2 comment Normality of Chaitin’s constantJust what I needed to know! Thanks, Doug. May28 comment Normality of Chaitin’s constant@Francois: I made it a community wiki because the request for a "guiding intuition" is a vague one, and when I've posted such questions in the past, people have complained "This should be a community wiki." But if I'm misunderstanding what community wiki status is for, please enlighten me! May28 revised Normality of Chaitin’s constantadded 135 characters in body May28 revised Normality of Chaitin’s constantdeleted 9 characters in body May28 asked Normality of Chaitin’s constant May24 awarded ● Nice Question May24 revised In what rigorous sense are Sperner’s Lemma and the Brouwer Fixed Point Theorem equivalent?added link to online version of article May23 comment Sperner’s lemma and Tucker’s lemma@Paul Taylor: See willamette.edu/~knyman/papers/Fan_Sperner.pdf for clear statements of Sperner's lemma and Tucker's lemma. May22 revised In what rigorous sense are Sperner’s Lemma and the Brouwer Fixed Point Theorem equivalent?added 106 characters in body May22 asked Sperner’s lemma and Tucker’s lemma May22 asked In what rigorous sense are Sperner’s Lemma and the Brouwer Fixed Point Theorem equivalent? May16 awarded ● Popular Question May4 awarded ● Popular Question Apr30 answered How exactly does Schützenberger promotion relate to Striker-Williams promotion? Apr17 awarded ● Taxonomist Apr12 comment Do all subtraction-free identities tropicalize?@quid: I've changed tropical-mathematics to tropical-arithmetic. Thanks for pointing out the existence of the tropical-arithmetic tag. Apr12 revised Do all subtraction-free identities tropicalize?edited tags; edited tags Apr10 comment Do all subtraction-free identities tropicalize?Colin and Will's answers are both convincing; thanks! One thing more I'd appreciate is a literature reference that I can cite if I publish something that makes use of this transfer principle. Given how straightforward the proof is (at least in hindsight), it's likely that some version of this result appears in some existing book or article. Apr10 revised Do all subtraction-free identities tropicalize?added 9 characters in body Apr10 asked Do all subtraction-free identities tropicalize? Mar24 revised Cyclically symmetric functionsedited body Mar24 comment Cyclically symmetric functionsThis reference is extremely well-written, and it covers lots if examples, but the cyclic action on the variables doesn't appear to be one of them (though Theorem 1.17 comes close; it's good to know that for the dihedral action, and all other finite Coxeter group actions, things work out about as nicely as one could hope). Mar24 asked Cyclically symmetric functions Mar14 answered constant averages along orbits Mar3 comment Using a quadratic kernel instead of a linear kernel in the Laplace transform@Liviu: Thanks, but I am confused. What is $s$? Also, does $L_{loc}^1$ mean locally integrable in the sense of being integrable over every finite interval, or is some sort of uniformity required? Mar2 asked Using a quadratic kernel instead of a linear kernel in the Laplace transform Feb14 awarded ● Notable Question Feb8 comment Galois connections@Jerome: Oh no -- a mistake in the very first paragraph of my article! Ah well; thanks for catching this error. I will fix it once I get LaTeX properly installed on my new Mac and can create pdfs again. Jan29 awarded ● Yearling Jan17 asked Bijective proof of Ramanujan’s congruence Jan17 awarded ● Popular Question