It is usually added as a binary independent variable.

In the special case where A is a binary variable:

Let denote the binary variables that equal 1 if point is visible in image and 0 otherwise.

Two binary variables are considered positively associated if most of the data falls along the diagonal cells.

In this case the attribute "age" is operationalized as a binary variable.

A simple example of an equation with binary variables is given below:

A game based on the algebra with binary variables can be visualized in many different ways.

In other words, they are the binary variables.

The solution can be obtained by reducing the problem into the equations with binary variables.

It is appropriate when the research question focuses on the degree of association between two binary variables.