Metamath Proof Explorer


Theorem sspsval

Description: Scalar multiplication on a subspace in terms of scalar multiplication on the parent space. (Contributed by NM, 28-Jan-2008) (New usage is discouraged.)

Ref Expression
Hypotheses ssps.y ⊢ 𝑌 = ( BaseSet ‘ 𝑊 )
ssps.s ⊢ 𝑆 = ( ·𝑠OLD ‘ 𝑈 )
ssps.r ⊢ 𝑅 = ( ·𝑠OLD ‘ 𝑊 )
ssps.h ⊢ 𝐻 = ( SubSp ‘ 𝑈 )
Assertion sspsval ( ( ( 𝑈 ∈ NrmCVec ∧ 𝑊 ∈ 𝐻 ) ∧ ( 𝐴 ∈ ℂ ∧ 𝐵 ∈ 𝑌 ) ) → ( 𝐴 𝑅 𝐵 ) = ( 𝐴 𝑆 𝐵 ) )

Proof

Step Hyp Ref Expression
1 ssps.y ⊢ 𝑌 = ( BaseSet ‘ 𝑊 )
2 ssps.s ⊢ 𝑆 = ( ·𝑠OLD ‘ 𝑈 )
3 ssps.r ⊢ 𝑅 = ( ·𝑠OLD ‘ 𝑊 )
4 ssps.h ⊢ 𝐻 = ( SubSp ‘ 𝑈 )
5 1 2 3 4 ssps ⊢ ( ( 𝑈 ∈ NrmCVec ∧ 𝑊 ∈ 𝐻 ) → 𝑅 = ( 𝑆 ↾ ( ℂ × 𝑌 ) ) )
6 5 oveqd ⊢ ( ( 𝑈 ∈ NrmCVec ∧ 𝑊 ∈ 𝐻 ) → ( 𝐴 𝑅 𝐵 ) = ( 𝐴 ( 𝑆 ↾ ( ℂ × 𝑌 ) ) 𝐵 ) )
7 ovres ⊢ ( ( 𝐴 ∈ ℂ ∧ 𝐵 ∈ 𝑌 ) → ( 𝐴 ( 𝑆 ↾ ( ℂ × 𝑌 ) ) 𝐵 ) = ( 𝐴 𝑆 𝐵 ) )
8 6 7 sylan9eq ⊢ ( ( ( 𝑈 ∈ NrmCVec ∧ 𝑊 ∈ 𝐻 ) ∧ ( 𝐴 ∈ ℂ ∧ 𝐵 ∈ 𝑌 ) ) → ( 𝐴 𝑅 𝐵 ) = ( 𝐴 𝑆 𝐵 ) )