Winter 2004 QG Seminar Errata
John Baez

On page 4 of week 1 it should say, at the very end,
"or S = emptyset".

On page 19 of week 2 the guess after "huh?!" doesn't
completely make sense, since F is the Fibonacci structure type,
we have an isomorphism between F and 1 + FZ + FZ^{2},
not FZ + FZ^{2}.

On page 19 of week 2 the isomorphism should read "G + GZ^{3}
is isomorphic to 1 + GZ + GZ^{2}".

On page 20 of week 2 there is, not exactly an error, but certainly
an infelicity: we are mainly using "S" to stand for an
arbitrary set, but also using it in the expression "SV"
to stand for the symmetric algebra on a vector space V.

On page 36 of week 4 the equation "P(4) = 4"
should read "P(4) = 5" 
this is an example of Ramanujan's theorem that P(5m+4) is congruent
to 0 mod 5.

On page 43 of week 5 where it says "regular Borel
measures" it should
read "finite regular Borel measures".

On page 26 of week 5 the categories FinSet and CTherm should
be underlined. Recall that we underline a category to refer to
its "decategorification", that is, the set of isomorphism
classes of its objects. If we decategorify the 2rigs FinSet and
CTherm we get rigs, and the obvious functor from FinSet to CTherm
gives a homomorphism from the first rig to the second.
If you discover any other errors, please let me know, and
we'll try to correct them (the old fashioned way, using correction
fluid) and rescan the pages.
baez@math.removethis.ucr.andthis.edu
© 2004 John Baez and Derek Wise