What if we wanted to make sure our input was positive before we used it in a function?

To our rescue comes the absolute value function. By dividing the number by its magnitude, we can determine its direction.

If positive, we'll get $1,$ and if negative, we will get $-1.$

Now, we need to configure the positive-negative function to output binary, so that we can use it as a building block later. This means outputting $1$ if it is positive, and $0$ if it is negative.  

Success!