Metamath Proof Explorer


Theorem lcd0

Description: The zero scalar of the closed kernel dual of a vector space. (Contributed by NM, 20-Mar-2015)

Ref Expression
Hypotheses lcd0.h ⊢ 𝐻 = ( LHyp ‘ 𝐾 )
lcd0.u ⊢ 𝑈 = ( ( DVecH ‘ 𝐾 ) ‘ 𝑊 )
lcd0.f ⊢ 𝐹 = ( Scalar ‘ 𝑈 )
lcd0.z ⊢ 0 = ( 0g ‘ 𝐹 )
lcd0.c ⊢ 𝐶 = ( ( LCDual ‘ 𝐾 ) ‘ 𝑊 )
lcd0.s ⊢ 𝑆 = ( Scalar ‘ 𝐶 )
lcd0.o ⊢ 𝑂 = ( 0g ‘ 𝑆 )
lcd0.k ⊢ ( 𝜑 → ( 𝐾 ∈ HL ∧ 𝑊 ∈ 𝐻 ) )
Assertion lcd0 ( 𝜑 → 𝑂 = 0 )

Proof

Step Hyp Ref Expression
1 lcd0.h ⊢ 𝐻 = ( LHyp ‘ 𝐾 )
2 lcd0.u ⊢ 𝑈 = ( ( DVecH ‘ 𝐾 ) ‘ 𝑊 )
3 lcd0.f ⊢ 𝐹 = ( Scalar ‘ 𝑈 )
4 lcd0.z ⊢ 0 = ( 0g ‘ 𝐹 )
5 lcd0.c ⊢ 𝐶 = ( ( LCDual ‘ 𝐾 ) ‘ 𝑊 )
6 lcd0.s ⊢ 𝑆 = ( Scalar ‘ 𝐶 )
7 lcd0.o ⊢ 𝑂 = ( 0g ‘ 𝑆 )
8 lcd0.k ⊢ ( 𝜑 → ( 𝐾 ∈ HL ∧ 𝑊 ∈ 𝐻 ) )
9 eqid ⊢ ( oppr ‘ 𝐹 ) = ( oppr ‘ 𝐹 )
10 1 2 3 9 5 6 8 lcdsca ⊢ ( 𝜑 → 𝑆 = ( oppr ‘ 𝐹 ) )
11 10 fveq2d ⊢ ( 𝜑 → ( 0g ‘ 𝑆 ) = ( 0g ‘ ( oppr ‘ 𝐹 ) ) )
12 9 4 oppr0 ⊢ 0 = ( 0g ‘ ( oppr ‘ 𝐹 ) )
13 11 7 12 3eqtr4g ⊢ ( 𝜑 → 𝑂 = 0 )