# A complex matter of relations (What am I?)

There is many-a-kind of number,

which sometimes makes me feel dumber.

Let's say that we start from zero to four,

and see if that leads us to learn some more.

Some numbers you might see as a product,

taken from a cart, just so you got it.

These numbers have special twins that keep it real,

and in so doing their nature conceal.

Relations are a part of all kinds graphs,

big ones, small ones, and also digraphs.

At the risk of a little frustration,

what is my relation?

Hint 1

The nodes have some sort of relation to complex numbers.

the product of complex conjugates $$(x+yi)(x-yi) = x^2+y^2$$ or $$(z+zi)(z-zi) = z^2+z^2$$
where $$x, y$$ represent values of parent nodes and $$z$$ represent the value from single parent node in terms of the graph.
The nodes $$x$$ and $$y$$ connect to $$x^2+y^2$$ (e.g. $$0$$ and $$4$$ to $$0^2+4^2=16$$, $$1$$ and $$2$$ to $$1^2+2^2=5$$ etc.). If $$x=y$$, it's only 1 edge. The relation to complex numbers may be that $$x^2+y^2$$ is the squared absolute value of $$x+yi$$, i.e. $$|x+yi|^2=x^2+y^2$$, or the product of complex conjugates $$(x+yi)(x-yi)$$. So, the relation can be complex conjugation.