Metamath Proof Explorer


Theorem hi02

Description: Inner product with the 0 vector. (Contributed by NM, 13-Oct-1999) (New usage is discouraged.)

Ref Expression
Assertion hi02 ( 𝐴 ∈ ℋ → ( 𝐴 ·ih 0 ) = 0 )

Proof

Step Hyp Ref Expression
1 ax-hv0cl 0 ∈ ℋ
2 ax-his1 ( ( 𝐴 ∈ ℋ ∧ 0 ∈ ℋ ) → ( 𝐴 ·ih 0 ) = ( ∗ ‘ ( 0 ·ih 𝐴 ) ) )
3 1 2 mpan2 ( 𝐴 ∈ ℋ → ( 𝐴 ·ih 0 ) = ( ∗ ‘ ( 0 ·ih 𝐴 ) ) )
4 hi01 ( 𝐴 ∈ ℋ → ( 0 ·ih 𝐴 ) = 0 )
5 4 fveq2d ( 𝐴 ∈ ℋ → ( ∗ ‘ ( 0 ·ih 𝐴 ) ) = ( ∗ ‘ 0 ) )
6 cj0 ( ∗ ‘ 0 ) = 0
7 5 6 eqtrdi ( 𝐴 ∈ ℋ → ( ∗ ‘ ( 0 ·ih 𝐴 ) ) = 0 )
8 3 7 eqtrd ( 𝐴 ∈ ℋ → ( 𝐴 ·ih 0 ) = 0 )