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 A B C D A + B = C + D A - C = D - B

Proof

Step Hyp Ref Expression
1 hvaddcl A B A + B
2 1 adantr A B C D A + B
3 hvaddcl C D C + D
4 3 adantl A B C D C + D
5 hvaddcl C B C + B
6 5 ancoms B C C + B
7 6 ad2ant2lr A B C D C + B
8 hvsubcan2 A + B C + D C + B A + B - C + B = C + D - C + B A + B = C + D
9 2 4 7 8 syl3anc A B C D A + B - C + B = C + D - C + B A + B = C + D
10 simpr A B B
11 10 anim2i C A B C B
12 11 ancoms A B C C B
13 hvsub4 A B C B A + B - C + B = A - C + B - B
14 12 13 syldan A B C A + B - C + B = A - C + B - B
15 hvsubid B B - B = 0
16 15 ad2antlr A B C B - B = 0
17 16 oveq2d A B C A - C + B - B = A - C + 0
18 hvsubcl A C A - C
19 ax-hvaddid A - C A - C + 0 = A - C
20 18 19 syl A C A - C + 0 = A - C
21 20 adantlr A B C A - C + 0 = A - C
22 14 17 21 3eqtrd A B C A + B - C + B = A - C
23 22 adantrr A B C D A + B - C + B = A - C
24 simpl C D C
25 24 anim1i C D B C B
26 hvsub4 C D C B C + D - C + B = C - C + D - B
27 25 26 syldan C D B C + D - C + B = C - C + D - B
28 hvsubid C C - C = 0
29 28 ad2antrr C D B C - C = 0
30 29 oveq1d C D B C - C + D - B = 0 + D - B
31 hvsubcl D B D - B
32 hvaddid2 D - B 0 + D - B = D - B
33 31 32 syl D B 0 + D - B = D - B
34 33 adantll C D B 0 + D - B = D - B
35 27 30 34 3eqtrd C D B C + D - C + B = D - B
36 35 ancoms B C D C + D - C + B = D - B
37 36 adantll A B C D C + D - C + B = D - B
38 23 37 eqeq12d A B C D A + B - C + B = C + D - C + B A - C = D - B
39 9 38 bitr3d A B C D A + B = C + D A - C = D - B