Metamath Proof Explorer


Theorem hiidrcl

Description: Real closure of inner product with self. (Contributed by NM, 29-May-1999) (New usage is discouraged.)

Ref Expression
Assertion hiidrcl ( 𝐴 ∈ ℋ → ( 𝐴 ·ih 𝐴 ) ∈ ℝ )

Proof

Step Hyp Ref Expression
1 eqid ( 𝐴 ·ih 𝐴 ) = ( 𝐴 ·ih 𝐴 )
2 hire ( ( 𝐴 ∈ ℋ ∧ 𝐴 ∈ ℋ ) → ( ( 𝐴 ·ih 𝐴 ) ∈ ℝ ↔ ( 𝐴 ·ih 𝐴 ) = ( 𝐴 ·ih 𝐴 ) ) )
3 1 2 mpbiri ( ( 𝐴 ∈ ℋ ∧ 𝐴 ∈ ℋ ) → ( 𝐴 ·ih 𝐴 ) ∈ ℝ )
4 3 anidms ( 𝐴 ∈ ℋ → ( 𝐴 ·ih 𝐴 ) ∈ ℝ )