Metamath Proof Explorer


Theorem scmatrhmval

Description: The value of the ring homomorphism F . (Contributed by AV, 22-Dec-2019)

Ref Expression
Hypotheses scmatrhmval.k ⊢ 𝐾 = ( Base ‘ 𝑅 )
scmatrhmval.a ⊢ 𝐴 = ( 𝑁 Mat 𝑅 )
scmatrhmval.o ⊢ 1 = ( 1r ‘ 𝐴 )
scmatrhmval.t ⊢ ∗ = ( ·𝑠 ‘ 𝐴 )
scmatrhmval.f ⊢ 𝐹 = ( 𝑥 ∈ 𝐾 ↦ ( 𝑥 ∗ 1 ) )
Assertion scmatrhmval ( ( 𝑅 ∈ 𝑉 ∧ 𝑋 ∈ 𝐾 ) → ( 𝐹 ‘ 𝑋 ) = ( 𝑋 ∗ 1 ) )

Proof

Step Hyp Ref Expression
1 scmatrhmval.k ⊢ 𝐾 = ( Base ‘ 𝑅 )
2 scmatrhmval.a ⊢ 𝐴 = ( 𝑁 Mat 𝑅 )
3 scmatrhmval.o ⊢ 1 = ( 1r ‘ 𝐴 )
4 scmatrhmval.t ⊢ ∗ = ( ·𝑠 ‘ 𝐴 )
5 scmatrhmval.f ⊢ 𝐹 = ( 𝑥 ∈ 𝐾 ↦ ( 𝑥 ∗ 1 ) )
6 oveq1 ⊢ ( 𝑥 = 𝑋 → ( 𝑥 ∗ 1 ) = ( 𝑋 ∗ 1 ) )
7 simpr ⊢ ( ( 𝑅 ∈ 𝑉 ∧ 𝑋 ∈ 𝐾 ) → 𝑋 ∈ 𝐾 )
8 ovexd ⊢ ( ( 𝑅 ∈ 𝑉 ∧ 𝑋 ∈ 𝐾 ) → ( 𝑋 ∗ 1 ) ∈ V )
9 5 6 7 8 fvmptd3 ⊢ ( ( 𝑅 ∈ 𝑉 ∧ 𝑋 ∈ 𝐾 ) → ( 𝐹 ‘ 𝑋 ) = ( 𝑋 ∗ 1 ) )