Metamath Proof Explorer


Theorem mulvval

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

Ref Expression
Assertion mulvval ACBDAvB=vABv

Proof

Step Hyp Ref Expression
1 elex ACAV
2 elex BDBV
3 fveq1 y=Byv=Bv
4 oveq12 x=Ayv=Bvxyv=ABv
5 3 4 sylan2 x=Ay=Bxyv=ABv
6 5 mpteq2dv x=Ay=Bvxyv=vABv
7 df-mulv v=xV,yVvxyv
8 reex V
9 8 mptex vABvV
10 6 7 9 ovmpoa AVBVAvB=vABv
11 1 2 10 syl2an ACBDAvB=vABv