Any numbers being Complex numbers

[Anachronistic]

Are there any numbers that is not considered to be a subset of a complex number subset of

a + bi

Where a and b are real numbers?

 

[micromass]

Define "number".

I'm asking because the concept of number is not well-defined in mathematics. There are a lot of things which carry the name "number", like real number, transfinite number, p-adic number, hyperreal number, etc. All these things are called numbers and often have no obvious relationship to each other. The concept of a number is too broad. It is not defined in mathematics.

 

[nonequilibrium]

I don't know as much as micromass on this subject, but I just read this on wikipedia and I think it might interest the OP.

On the wiki page of Number, it says under the header "Complex Numbers" the following:

Sets of numbers that are not subsets of the complex numbers are sometimes called hypercomplex numbers.

which is the same wording at the OP used, so maybe he chould check out hypercomplex numbers.

 

[ohwilleke]

Numerical quantities described with vectors of more than two elements or tensors cannot, as a general rule, be described as complex numbers.