Metamath Proof Explorer


Theorem ipval2lem4

Description: Lemma for ipval3 . (Contributed by NM, 1-Feb-2007) (New usage is discouraged.)

Ref Expression
Hypotheses dipfval.1 ⊢ 𝑋 = ( BaseSet ‘ 𝑈 )
dipfval.2 ⊢ 𝐺 = ( +𝑣 ‘ 𝑈 )
dipfval.4 ⊢ 𝑆 = ( ·𝑠OLD ‘ 𝑈 )
dipfval.6 ⊢ 𝑁 = ( normCV ‘ 𝑈 )
dipfval.7 ⊢ 𝑃 = ( ·𝑖OLD ‘ 𝑈 )
Assertion ipval2lem4 ( ( ( 𝑈 ∈ NrmCVec ∧ 𝐴 ∈ 𝑋 ∧ 𝐵 ∈ 𝑋 ) ∧ 𝐶 ∈ ℂ ) → ( ( 𝑁 ‘ ( 𝐴 𝐺 ( 𝐶 𝑆 𝐵 ) ) ) ↑ 2 ) ∈ ℂ )

Proof

Step Hyp Ref Expression
1 dipfval.1 ⊢ 𝑋 = ( BaseSet ‘ 𝑈 )
2 dipfval.2 ⊢ 𝐺 = ( +𝑣 ‘ 𝑈 )
3 dipfval.4 ⊢ 𝑆 = ( ·𝑠OLD ‘ 𝑈 )
4 dipfval.6 ⊢ 𝑁 = ( normCV ‘ 𝑈 )
5 dipfval.7 ⊢ 𝑃 = ( ·𝑖OLD ‘ 𝑈 )
6 1 2 3 4 5 ipval2lem2 ⊢ ( ( ( 𝑈 ∈ NrmCVec ∧ 𝐴 ∈ 𝑋 ∧ 𝐵 ∈ 𝑋 ) ∧ 𝐶 ∈ ℂ ) → ( ( 𝑁 ‘ ( 𝐴 𝐺 ( 𝐶 𝑆 𝐵 ) ) ) ↑ 2 ) ∈ ℝ )
7 6 recnd ⊢ ( ( ( 𝑈 ∈ NrmCVec ∧ 𝐴 ∈ 𝑋 ∧ 𝐵 ∈ 𝑋 ) ∧ 𝐶 ∈ ℂ ) → ( ( 𝑁 ‘ ( 𝐴 𝐺 ( 𝐶 𝑆 𝐵 ) ) ) ↑ 2 ) ∈ ℂ )