Metamath Proof Explorer


Theorem kbval

Description: The value of the operator resulting from the outer product | A >. <. B | of two vectors. Equation 8.1 of Prugovecki p. 376. (Contributed by NM, 15-May-2006) (Revised by Mario Carneiro, 16-Nov-2013) (New usage is discouraged.)

Ref Expression
Assertion kbval ( ( 𝐴 ∈ ℋ ∧ 𝐵 ∈ ℋ ∧ 𝐶 ∈ ℋ ) → ( ( 𝐴 ketbra 𝐵 ) ‘ 𝐶 ) = ( ( 𝐶 ·ih 𝐵 ) · 𝐴 ) )

Proof

Step Hyp Ref Expression
1 kbfval ( ( 𝐴 ∈ ℋ ∧ 𝐵 ∈ ℋ ) → ( 𝐴 ketbra 𝐵 ) = ( 𝑥 ∈ ℋ ↦ ( ( 𝑥 ·ih 𝐵 ) · 𝐴 ) ) )
2 1 fveq1d ( ( 𝐴 ∈ ℋ ∧ 𝐵 ∈ ℋ ) → ( ( 𝐴 ketbra 𝐵 ) ‘ 𝐶 ) = ( ( 𝑥 ∈ ℋ ↦ ( ( 𝑥 ·ih 𝐵 ) · 𝐴 ) ) ‘ 𝐶 ) )
3 oveq1 ( 𝑥 = 𝐶 → ( 𝑥 ·ih 𝐵 ) = ( 𝐶 ·ih 𝐵 ) )
4 3 oveq1d ( 𝑥 = 𝐶 → ( ( 𝑥 ·ih 𝐵 ) · 𝐴 ) = ( ( 𝐶 ·ih 𝐵 ) · 𝐴 ) )
5 eqid ( 𝑥 ∈ ℋ ↦ ( ( 𝑥 ·ih 𝐵 ) · 𝐴 ) ) = ( 𝑥 ∈ ℋ ↦ ( ( 𝑥 ·ih 𝐵 ) · 𝐴 ) )
6 ovex ( ( 𝐶 ·ih 𝐵 ) · 𝐴 ) ∈ V
7 4 5 6 fvmpt ( 𝐶 ∈ ℋ → ( ( 𝑥 ∈ ℋ ↦ ( ( 𝑥 ·ih 𝐵 ) · 𝐴 ) ) ‘ 𝐶 ) = ( ( 𝐶 ·ih 𝐵 ) · 𝐴 ) )
8 2 7 sylan9eq ( ( ( 𝐴 ∈ ℋ ∧ 𝐵 ∈ ℋ ) ∧ 𝐶 ∈ ℋ ) → ( ( 𝐴 ketbra 𝐵 ) ‘ 𝐶 ) = ( ( 𝐶 ·ih 𝐵 ) · 𝐴 ) )
9 8 3impa ( ( 𝐴 ∈ ℋ ∧ 𝐵 ∈ ℋ ∧ 𝐶 ∈ ℋ ) → ( ( 𝐴 ketbra 𝐵 ) ‘ 𝐶 ) = ( ( 𝐶 ·ih 𝐵 ) · 𝐴 ) )