Metamath Proof Explorer


Theorem axicn

Description: _i is a complex number. Axiom 3 of 22 for real and complex numbers, derived from ZF set theory. This construction-dependent theorem should not be referenced directly; instead, use ax-icn . (Contributed by NM, 23-Feb-1996) (New usage is discouraged.)

Ref Expression
Assertion axicn ⊢ i ∈ ℂ

Proof

Step Hyp Ref Expression
1 0r ⊢ 0 𝑹 ∈ 𝑹
2 1sr ⊢ 1 𝑹 ∈ 𝑹
3 df-i ⊢ i = 0 𝑹 1 𝑹
4 3 eleq1i ⊢ i ∈ ℂ ↔ 0 𝑹 1 𝑹 ∈ ℂ
5 opelcn ⊢ 0 𝑹 1 𝑹 ∈ ℂ ↔ 0 𝑹 ∈ 𝑹 ∧ 1 𝑹 ∈ 𝑹
6 4 5 bitri ⊢ i ∈ ℂ ↔ 0 𝑹 ∈ 𝑹 ∧ 1 𝑹 ∈ 𝑹
7 1 2 6 mpbir2an ⊢ i ∈ ℂ