Metamath Proof Explorer


Theorem hvadd4

Description: Hilbert vector space addition law. (Contributed by NM, 16-Oct-1999) (New usage is discouraged.)

Ref Expression
Assertion hvadd4 ABCDA+B+C+D=A+C+B+D

Proof

Step Hyp Ref Expression
1 hvadd32 ABCA+B+C=A+C+B
2 1 oveq1d ABCA+B+C+D=A+C+B+D
3 2 3expa ABCA+B+C+D=A+C+B+D
4 3 adantrr ABCDA+B+C+D=A+C+B+D
5 hvaddcl ABA+B
6 ax-hvass A+BCDA+B+C+D=A+B+C+D
7 6 3expb A+BCDA+B+C+D=A+B+C+D
8 5 7 sylan ABCDA+B+C+D=A+B+C+D
9 hvaddcl ACA+C
10 ax-hvass A+CBDA+C+B+D=A+C+B+D
11 10 3expb A+CBDA+C+B+D=A+C+B+D
12 9 11 sylan ACBDA+C+B+D=A+C+B+D
13 12 an4s ABCDA+C+B+D=A+C+B+D
14 4 8 13 3eqtr3d ABCDA+B+C+D=A+C+B+D