Complex number
Set
definiendum | C≡R2 |
Discussion
We write the complex numbers as a+ib≡⟨a,b⟩, where a,b∈R. The complex numbers are then set up as a field with i2=−1, see arithmetic structure of complex numbers. We identify the real numbers within C as the set of elements of the form ⟨a,0⟩=a+i0=a.
Reference
Wikipedia: Complex number