The Stacks project

Messed up the primes

Thanks to OS and William Chen
https://stacks.math.columbia.edu/tag/046S#comment-1813
https://stacks.math.columbia.edu/tag/046S#comment-3226

Fix typo in spaecs-groupoids

Thanks to OS
http://stacks.math.columbia.edu/tag/046S#comment-1813

When is a map of quotient stacks a gerbe?

	The lemma gives sufficient conditions.

Terminology:
	"group space" ---> "group algebraic space"
	"groupoid space" ---> "groupoid in algebraic spaces"

	It seems more natural this way to at least three people, and in
	any case it prevents the possible confusion that may arise from
	the fact that in some places in the literature the word "space"
	sometimes refers to any sheaf on schemes in the fppf topology.

Tags: added new tags

Restriction and equivalences

	We inserted a couple of lemmas describing when the restriction
	of a groupoid scheme gives rise to an isomorphic quotient sheaf
	or when it gives rise to an equivalent quotient stack.