Metamath Proof Explorer


Theorem hhssvs

Description: The vector subtraction operation on a subspace. (Contributed by NM, 10-Apr-2008) (New usage is discouraged.)

Ref Expression
Hypotheses hhsssh2.1 W = + H × H × H norm H
hhssba.2 H S
Assertion hhssvs - H × H = - v W

Proof

Step Hyp Ref Expression
1 hhsssh2.1 W = + H × H × H norm H
2 hhssba.2 H S
3 eqid + norm = + norm
4 3 hhnv + norm NrmCVec
5 3 1 hhsst H S W SubSp + norm
6 2 5 ax-mp W SubSp + norm
7 1 2 hhssba H = BaseSet W
8 3 hhvs - = - v + norm
9 eqid - v W = - v W
10 eqid SubSp + norm = SubSp + norm
11 7 8 9 10 sspm + norm NrmCVec W SubSp + norm - v W = - H × H
12 4 6 11 mp2an - v W = - H × H
13 12 eqcomi - H × H = - v W