MR and Sergei,
Sorry to return again to Hofstadter but his book demonstrates Sergei's
point and counterpoint since it shows how a same matrix may give origin to
Bach ( and contrapunctus), Escher's representations of hands that draw
themselves and the Moebius band and Goedel's ideas countering B.Russel's
about what is contained where and ...sorry, I forgot how one says /'groups/'
in English- Math, in Portuguese we say "conjunto" and I don't have
Hofstadter's book.
The idea is that counterpoint ,in music, may be drawn in figurative art
,expressed mathematically or in Symbolic Logic and inspire a written text.

I know it not fair play to make unsupported affirmations. I have written
on Hofstadter before (elsewhere), but unfortunately cannot abandon
current tasks to dig for justification. For now let me say that I most
strongly disagree with such a recommendation.

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