Metamath Proof Explorer


Theorem hvsubadd

Description: Relationship between vector subtraction and addition. (Contributed by NM, 30-Oct-1999) (New usage is discouraged.)

Ref Expression
Assertion hvsubadd ABCA-B=CB+C=A

Proof

Step Hyp Ref Expression
1 oveq1 A=ifAA0A-B=ifAA0-B
2 1 eqeq1d A=ifAA0A-B=CifAA0-B=C
3 eqeq2 A=ifAA0B+C=AB+C=ifAA0
4 2 3 bibi12d A=ifAA0A-B=CB+C=AifAA0-B=CB+C=ifAA0
5 oveq2 B=ifBB0ifAA0-B=ifAA0-ifBB0
6 5 eqeq1d B=ifBB0ifAA0-B=CifAA0-ifBB0=C
7 oveq1 B=ifBB0B+C=ifBB0+C
8 7 eqeq1d B=ifBB0B+C=ifAA0ifBB0+C=ifAA0
9 6 8 bibi12d B=ifBB0ifAA0-B=CB+C=ifAA0ifAA0-ifBB0=CifBB0+C=ifAA0
10 eqeq2 C=ifCC0ifAA0-ifBB0=CifAA0-ifBB0=ifCC0
11 oveq2 C=ifCC0ifBB0+C=ifBB0+ifCC0
12 11 eqeq1d C=ifCC0ifBB0+C=ifAA0ifBB0+ifCC0=ifAA0
13 10 12 bibi12d C=ifCC0ifAA0-ifBB0=CifBB0+C=ifAA0ifAA0-ifBB0=ifCC0ifBB0+ifCC0=ifAA0
14 ifhvhv0 ifAA0
15 ifhvhv0 ifBB0
16 ifhvhv0 ifCC0
17 14 15 16 hvsubaddi ifAA0-ifBB0=ifCC0ifBB0+ifCC0=ifAA0
18 4 9 13 17 dedth3h ABCA-B=CB+C=A