Theorem chex

Description: The set of closed subspaces of a Hilbert space exists (is a set). (Contributed by NM, 23-Oct-1999) (New usage is discouraged.)

	Ref	Expression
Assertion	chex	|- CH e. _V

Proof

Step	Hyp	Ref	Expression
1		shex	|- SH e. _V
2		chsssh	|- CH C_ SH
3	1 2	ssexi	|- CH e. _V