Metamath Proof Explorer


Theorem addrval

Description: Value of the operation of vector addition. (Contributed by Andrew Salmon, 27-Jan-2012)

Ref Expression
Assertion addrval A C B D A + r B = v A v + B v

Proof

Step Hyp Ref Expression
1 elex A C A V
2 elex B D B V
3 fveq1 x = A x v = A v
4 fveq1 y = B y v = B v
5 3 4 oveqan12d x = A y = B x v + y v = A v + B v
6 5 mpteq2dv x = A y = B v x v + y v = v A v + B v
7 df-addr + r = x V , y V v x v + y v
8 reex V
9 8 mptex v A v + B v V
10 6 7 9 ovmpoa A V B V A + r B = v A v + B v
11 1 2 10 syl2an A C B D A + r B = v A v + B v