Metamath Proof Explorer


Theorem hvaddsub4

Description: Hilbert vector space addition/subtraction law. (Contributed by NM, 18-May-2005) (New usage is discouraged.)

Ref Expression
Assertion hvaddsub4 ABCDA+B=C+DA-C=D-B

Proof

Step Hyp Ref Expression
1 hvaddcl ABA+B
2 1 adantr ABCDA+B
3 hvaddcl CDC+D
4 3 adantl ABCDC+D
5 hvaddcl CBC+B
6 5 ancoms BCC+B
7 6 ad2ant2lr ABCDC+B
8 hvsubcan2 A+BC+DC+BA+B-C+B=C+D-C+BA+B=C+D
9 2 4 7 8 syl3anc ABCDA+B-C+B=C+D-C+BA+B=C+D
10 simpr ABB
11 10 anim2i CABCB
12 11 ancoms ABCCB
13 hvsub4 ABCBA+B-C+B=A-C+B-B
14 12 13 syldan ABCA+B-C+B=A-C+B-B
15 hvsubid BB-B=0
16 15 ad2antlr ABCB-B=0
17 16 oveq2d ABCA-C+B-B=A-C+0
18 hvsubcl ACA-C
19 ax-hvaddid A-CA-C+0=A-C
20 18 19 syl ACA-C+0=A-C
21 20 adantlr ABCA-C+0=A-C
22 14 17 21 3eqtrd ABCA+B-C+B=A-C
23 22 adantrr ABCDA+B-C+B=A-C
24 simpl CDC
25 24 anim1i CDBCB
26 hvsub4 CDCBC+D-C+B=C-C+D-B
27 25 26 syldan CDBC+D-C+B=C-C+D-B
28 hvsubid CC-C=0
29 28 ad2antrr CDBC-C=0
30 29 oveq1d CDBC-C+D-B=0+D-B
31 hvsubcl DBD-B
32 hvaddlid D-B0+D-B=D-B
33 31 32 syl DB0+D-B=D-B
34 33 adantll CDB0+D-B=D-B
35 27 30 34 3eqtrd CDBC+D-C+B=D-B
36 35 ancoms BCDC+D-C+B=D-B
37 36 adantll ABCDC+D-C+B=D-B
38 23 37 eqeq12d ABCDA+B-C+B=C+D-C+BA-C=D-B
39 9 38 bitr3d ABCDA+B=C+DA-C=D-B