When I was teaching the summer camp in CTY, students started to write:
{
in Z+|
< 0} = a really happy negative number
{
in Z+|
is even and n is odd} = 2, ( a really odd even number)
I thought it is really cute, I shared it 80 , he came up with some more statment ….
But we will go over a little math background first.
is the set of real numbers, which can be thought of as points on an infinitely long line, a real line.
is the set of integers, such as
represents the set of Complex numbers, they can be expressed in
.
and
are Real numbers, and
is known as the imaginary number, the solution of
.

Bess-Hamiti / Pixabay
= a real complex number
is a complex real number
is a complex complex number
English Teacher: I am imaginary
Math Teacher: is imaginary
Descartes: I exist because I think.
Empty set: I exist because I set.
: I exist because I imagine.
Lie algebra: you all go to hell.