The Stacks project

Try to use L/K notation for field extensions

We could also try to consistenly use "field extension" and not just
"extension" and consistently use "ring extension", etc.

Add f in schemes

Thanks to Jérôme Poineau
https://stacks.math.columbia.edu/tag/01J8#comment-4996

Whitespace changes

LaTeX: \Spec

	Introduced the macro

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

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

Reorganize schemes.tex

	Actually one of the two lemmas of the previous commit was
	already there. This forced some reorganization.

Closed points in fibres

	Given a specialization x ---> x' of points in X and a morphism X
	---> S of finite type, you can, if x' is closed in its fibre, a
	sequence of specializations x ---> x_1 ---> x' such that x_1 is
	closed in its fibre and in the same fibre as x.

Started tags infrastructure

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

Separation properties

	modified:   algebra.tex
	modified:   schemes.tex