The Stacks project

Formulate using subcover

Thanks to Patrick Rabau
https://stacks.math.columbia.edu/tag/0059#comment-6508

Varieties: Uniqueness base field

	If X is a connected reduced scheme of finite type over a field
	then it has a unique maximal base field. (Not field of
	definition which is a completely different animal.)

Various edits: More robust tex

	We removed any math environments from section headings, as well
	as all references. In addition a theorem environment should not
	start with a enumerate environment, since on the one hand it
	looks bad, and on the other hand it seems texlive 2009 does not
	correctly handle this.

Started tags infrastructure

	new file:   scripts/add_tags.py
	modified:   scripts/functions.py
	new file:   tags/initial_tags
	new file:   tags/tags

	modified:   algebra.tex
	modified:   topology.tex

New file for topological stuff.

	modified:   Makefile
	modified:   algebra.tex
	modified:   categories.tex
	modified:   chapters.tex
	modified:   my.bib
	modified:   preamble.tex
	new file:   topology.tex