Metamath Proof Explorer


Theorem hvsub4

Description: Hilbert vector space addition/subtraction law. (Contributed by NM, 17-Oct-1999) (New usage is discouraged.)

Ref Expression
Assertion hvsub4 ABCDA+B-C+D=A-C+B-D

Proof

Step Hyp Ref Expression
1 hvaddcl ABA+B
2 hvaddcl CDC+D
3 hvsubval A+BC+DA+B-C+D=A+B+-1C+D
4 1 2 3 syl2an ABCDA+B-C+D=A+B+-1C+D
5 hvsubval ACA-C=A+-1C
6 5 ad2ant2r ABCDA-C=A+-1C
7 hvsubval BDB-D=B+-1D
8 7 ad2ant2l ABCDB-D=B+-1D
9 6 8 oveq12d ABCDA-C+B-D=A+-1C+B+-1D
10 neg1cn 1
11 ax-hvdistr1 1CD-1C+D=-1C+-1D
12 10 11 mp3an1 CD-1C+D=-1C+-1D
13 12 adantl ABCD-1C+D=-1C+-1D
14 13 oveq2d ABCDA+B+-1C+D=A+B+-1C+-1D
15 hvmulcl 1C-1C
16 10 15 mpan C-1C
17 16 anim2i ACA-1C
18 hvmulcl 1D-1D
19 10 18 mpan D-1D
20 19 anim2i BDB-1D
21 17 20 anim12i ACBDA-1CB-1D
22 21 an4s ABCDA-1CB-1D
23 hvadd4 A-1CB-1DA+-1C+B+-1D=A+B+-1C+-1D
24 22 23 syl ABCDA+-1C+B+-1D=A+B+-1C+-1D
25 14 24 eqtr4d ABCDA+B+-1C+D=A+-1C+B+-1D
26 9 25 eqtr4d ABCDA-C+B-D=A+B+-1C+D
27 4 26 eqtr4d ABCDA+B-C+D=A-C+B-D