Metamath Proof Explorer


Theorem opelcn

Description: Ordered pair membership in the class of complex numbers. (Contributed by NM, 14-May-1996) (New usage is discouraged.)

Ref Expression
Assertion opelcn ( ⟨ 𝐴 , 𝐵 ⟩ ∈ ℂ ↔ ( 𝐴 ∈ R ∧ 𝐵 ∈ R ) )

Proof

Step Hyp Ref Expression
1 df-c ⊢ ℂ = ( R × R )
2 1 eleq2i ⊢ ( ⟨ 𝐴 , 𝐵 ⟩ ∈ ℂ ↔ ⟨ 𝐴 , 𝐵 ⟩ ∈ ( R × R ) )
3 opelxp ⊢ ( ⟨ 𝐴 , 𝐵 ⟩ ∈ ( R × R ) ↔ ( 𝐴 ∈ R ∧ 𝐵 ∈ R ) )
4 2 3 bitri ⊢ ( ⟨ 𝐴 , 𝐵 ⟩ ∈ ℂ ↔ ( 𝐴 ∈ R ∧ 𝐵 ∈ R ) )