Metamath Proof Explorer


Theorem cnims

Description: The metric induced on the complex numbers. cnmet proves that it is a metric. (Contributed by Steve Rodriguez, 5-Dec-2006) (Revised by NM, 15-Jan-2008) (New usage is discouraged.)

Ref Expression
Hypotheses cnims.6 𝑈 = ⟨ ⟨ + , · ⟩ , abs ⟩
cnims.7 𝐷 = ( abs ∘ − )
Assertion cnims 𝐷 = ( IndMet ‘ 𝑈 )

Proof

Step Hyp Ref Expression
1 cnims.6 𝑈 = ⟨ ⟨ + , · ⟩ , abs ⟩
2 cnims.7 𝐷 = ( abs ∘ − )
3 1 cnnv 𝑈 ∈ NrmCVec
4 1 cnnvm − = ( −𝑣𝑈 )
5 1 cnnvnm abs = ( normCV𝑈 )
6 eqid ( IndMet ‘ 𝑈 ) = ( IndMet ‘ 𝑈 )
7 4 5 6 imsval ( 𝑈 ∈ NrmCVec → ( IndMet ‘ 𝑈 ) = ( abs ∘ − ) )
8 3 7 ax-mp ( IndMet ‘ 𝑈 ) = ( abs ∘ − )
9 2 8 eqtr4i 𝐷 = ( IndMet ‘ 𝑈 )