nprofile1qy2hwumn8ghj7un9d3shjtnddaehgu3wwp6kyqpqez3yya8tpgge7lk4jq2zxz0cj3d2mcgev9mffd4ec7tfy84hre4sqchszg (nprofile…hszg) nprofile1qy2hwumn8ghj7un9d3shjtnddaehgu3wwp6kyqpqjd874v63430gng67kpw5m597f34dr9vr0yhkp8dkmnma8208raysyd6kk0 (nprofile…6kk0) nprofile1qy2hwumn8ghj7un9d3shjtnddaehgu3wwp6kyqpqqmshcslmwan3erj3ulczepe8q8a8xdyfkndnk8fudgtg8ccwg6zqlsl9jz (nprofile…l9jz) while working in Oxford, I noticed that there are topics which are claimed to be CS by people working at CS departments who enjoy CS-isation of maths. They take up a maths problem, cloak it into terminology and notation not used in this maths area, and march on churning out papers and books which go unnoticed by maths people, cause it's entirely under their radar.
(It could be that I, as usual, sound too harsh, but there is certainly quite a bit of this in the theory of nominal sets, for instance). I examined a CS MSc thesis on the topic once; then I send to the (very busy) thesis supervisor an email, like this:
"following our conversation regarding the MSc
thesis, I went and browsed a bit the book Nominal Sets by Pitts.
(I must say I didn't manage to get very far there).
I found it striking how little permutation group theory is used there, even though
there are easy reformulations of fundamental concepts. For instance,
any nominal set comes from the permutation action of the finitary group
\(G=Sym(\infty)\) (called \(Perm \mathbb{A}\) in the book),
with each orbit having the point stabilizer \(H\), with \(A\)
a finite subset of the domain of \(G\), and \(H\) contained in the setwise
stabilser \(G_{\{A\}}<G\) of \(A\), and containing the pointwise stabiliser \(G_A\) of \(A\).
I.e. \(G_{\{A\}}\geq H\geq G_A\).
(And for strong nominal sets \(H=G_A\) ).
All this immediately suggests that e.g. the natural \(G\)-invariant binary relations
associated with the nominal set in question are somehow "easy" to
understand.
[etc]"
Dima Pasechnik 🇺🇦 🇳🇱 /
npub1cc…9rjyc
2025-04-08 20:52:34
in reply to nevent1q…cay7
Author Public Key
npub1ccsatp4j3q6ajf3z3xcqe34ale74g4jaszrlfkqkp523kgu3n9usf9rjycPublished at
2025-04-08 20:52:34Event JSON
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