Metamath Proof Explorer


Theorem hhmetdval

Description: Value of the distance function of the metric space of Hilbert space. (Contributed by NM, 10-Apr-2008) (New usage is discouraged.)

Ref Expression
Hypotheses hhnv.1 U = + norm
hhims2.2 D = IndMet U
Assertion hhmetdval A B A D B = norm A - B

Proof

Step Hyp Ref Expression
1 hhnv.1 U = + norm
2 hhims2.2 D = IndMet U
3 1 hhnv U NrmCVec
4 1 hhba = BaseSet U
5 1 3 4 2 h2hmetdval A B A D B = norm A - B