Metamath Proof Explorer


Definition df-i

Description: Define the complex number _i (the imaginary unit). (Contributed by NM, 22-Feb-1996) (New usage is discouraged.)

Ref Expression
Assertion df-i i=0𝑹1𝑹

Detailed syntax breakdown

Step Hyp Ref Expression
0 ci classi
1 c0r class0𝑹
2 c1r class1𝑹
3 1 2 cop class0𝑹1𝑹
4 0 3 wceq wffi=0𝑹1𝑹