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.

LaTeX: \Spec

	Introduced the macro

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

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

Morphisms of Spaces: Valuative criterion + finite separable extensions

	In the existence part of the valuative criterion for algebraic
	spaces it is enough to take a finite separable extension of the
	fraction field of the dvr. It is sometimes also necessary. It
	seems that if the morphism is separated, then it shouldn't be
	necessary, but we'll return to that later.

Morphisms of Spaces: Valutaive criteria

	Allow for a field extension in the definition of the existence
	part of the valuative criterion for morphisms of algebraic
	spaces. Design decision: Any field extension is allowed. If one
	can get away with less (e.g. finite separable extensions or no
	extension at all) then this should be formulated in a separate
	lemma. We do this in the case of representable morphisms in this
	commit also.

Tags: New tags added and two fixed

Morphisms of spaces: Universally closed + valuative criteria

	Started writing a little more on universally closed morphisms of
	algebraic spaces and (possibly) valuative criteria. This seems
	to be already slightly tricky in our general setting.