# Jérôme JEAN-CHARLES

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## Registered User

 Name Jérôme JEAN-CHARLES Member for 3 years Seen yesterday Website Location Paris France Age 57
Subjects : finite maths , combinatorics, graphs , categories. I am problem oriented and of the geometric type. I believe the linguistic-literary side of maths should be put forward in particular as a means to fill the gap between mathematics and general culture.
 Mar30 comment Enumerating 0-1 finite boxes without null rays.@Casteels : OK you are right there was a typo the 4 and the 6 where exchanged in front of the powers ^p. Mar30 revised Enumerating 0-1 finite boxes without null rays.Exchange coeffs. 6 and 4 inf front of 7^p and 3^p Mar29 asked Enumerating 0-1 finite boxes without null rays. Mar3 revised Difficult examples for Frankl’s union-closed conjectureminor Mar2 revised Difficult examples for Frankl’s union-closed conjectureAdded a third point C) Mar1 answered Difficult examples for Frankl’s union-closed conjecture Feb8 comment Which finite group is not the automorphism group of some rooted finite trees Thank you very much , there is still an aspect of "density". Do we loose kind of "half" when restricting to (FTAG) FiniteTree-Automorphism -Groups ? Feb8 comment Which finite group is not the automorphism group of some rooted finite trees How funny that my context is in fact graph isomorphism and Brendan is the first to answer this. Mysterious or funny ? Feb8 comment Why is Set, and not Rel, so ubiquitous in mathematics?Too short and too partial for an answer: I think that functions are on the technical side whereas relation are on the conceptual side. A function (partial) "is" a partition whereas a relation thought as a bipartite graph is much more complicated. A related (no pun) question is that partial functions should be used instead of function. Feb8 asked Which finite group is not the automorphism group of some rooted finite trees Jan24 comment Galois connections@jim It is a detail : in galois.pdf the property is symetric (not reflexive as given). Dec25 comment What would you want to see at the Museum of Mathematics?@Todd : I have seen a very nice documentary about professional dancers at the Opéra de Paris ( from Reichenbach ? ) . You see them talk and act (dance) for training and interpreting, yet the "truth" they reach through successive corrections is felt but not understood (unless you are semi professional). So the idea is that people may understand the general aim and the kind of logic used by mathematicians without a proper grasp. Dec17 awarded ● Good Answer