Metamath Proof Explorer


Theorem abshicom

Description: Commuted inner products have the same absolute values. (Contributed by NM, 26-May-2006) (New usage is discouraged.)

Ref Expression
Assertion abshicom ( ( 𝐴 ∈ ℋ ∧ 𝐵 ∈ ℋ ) → ( abs ‘ ( 𝐴 ·ih 𝐵 ) ) = ( abs ‘ ( 𝐵 ·ih 𝐴 ) ) )

Proof

Step Hyp Ref Expression
1 ax-his1 ( ( 𝐴 ∈ ℋ ∧ 𝐵 ∈ ℋ ) → ( 𝐴 ·ih 𝐵 ) = ( ∗ ‘ ( 𝐵 ·ih 𝐴 ) ) )
2 1 fveq2d ( ( 𝐴 ∈ ℋ ∧ 𝐵 ∈ ℋ ) → ( abs ‘ ( 𝐴 ·ih 𝐵 ) ) = ( abs ‘ ( ∗ ‘ ( 𝐵 ·ih 𝐴 ) ) ) )
3 hicl ( ( 𝐵 ∈ ℋ ∧ 𝐴 ∈ ℋ ) → ( 𝐵 ·ih 𝐴 ) ∈ ℂ )
4 3 ancoms ( ( 𝐴 ∈ ℋ ∧ 𝐵 ∈ ℋ ) → ( 𝐵 ·ih 𝐴 ) ∈ ℂ )
5 4 abscjd ( ( 𝐴 ∈ ℋ ∧ 𝐵 ∈ ℋ ) → ( abs ‘ ( ∗ ‘ ( 𝐵 ·ih 𝐴 ) ) ) = ( abs ‘ ( 𝐵 ·ih 𝐴 ) ) )
6 2 5 eqtrd ( ( 𝐴 ∈ ℋ ∧ 𝐵 ∈ ℋ ) → ( abs ‘ ( 𝐴 ·ih 𝐵 ) ) = ( abs ‘ ( 𝐵 ·ih 𝐴 ) ) )