Oi todos,
acabei de submeter um artigo que ficou bem bacana, dxô fazer
propaganda dele aqui...
Título: "On the missing diagrams in Category Theory"
Links:
http://angg.twu.net/LATEX/2022on-the-missing.pdf
http://angg.twu.net/math-b.html#2022-md
Abstract:
Most texts on Category Theory are written in a very terse style, in
which people pretend a) that all concepts are visualizable, and b)
that the readers can reconstruct the diagrams that the authors had
in mind based on only the most essential cues. As an outsider I
spent years believing that the techniques for drawing diagrams were
part of the oral culture of the field, and that the insiders could
read texts on CT reconstructing the "missing diagrams" in them line
by line and paragraph by paragraph, and drawing for each page of
text a page of diagrams with all the diagrams that the authors had
omitted. My belief was wrong: there are lots of conventions for
drawing diagrams scattered through the literature, but that unified
diagrammatic language did not exist. In this chapter I will show an
attempt to reconstruct that (imaginary) language for missing
diagrams: we will see an extensible diagrammatic language, called
DL, that follows the conventions of the diagrams in the literature
of CT whenever possible and that seems to be adequate for drawing
"missing diagrams" for Category Theory. Our examples include the
"missing diagrams" for adjunctions, for the Yoneda Lemma, for Kan
extensions, and for geometric morphisms, and how to formalize them
in Agda.
[[]] =),
Eduardo Ochs
http://angg.twu.net/math-b.html