The Stacks project

Remove a word in statement lemma in algebra

Thanks to Matthieu Romagny
https://stacks.math.columbia.edu/tag/00I7#comment-3395

zerodivisor and nonzerodivisor

	Seems better this way.

Whitespace changes

LaTeX: \Spec

	Introduced the macro

	\def\Spec{\mathop{\rm Spec}}

	and changed all the occurences of \text{Spec} into \Spec.

Groupoids: More properties of group schemes over fields

	Smoothness in characteristic zero (finite type case)
	Smoothness if reduced over perfect field
	Open subgroups are closed
	Locally closed subgroups are closed
	Existence of open and closed subgroup scheme which is a
		countable union of affine opens

Started tags infrastructure

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

Starting with varieties.tex

	modified:   algebra.tex
	modified:   properties.tex
	modified:   topology.tex
	new file:   varieties.tex