# Learning From Data – A Short Course: Problem 7.1

**Page 43**

Implement the decision function below using a 3-layer perceptron.

First I’ll construct a rectangle like this:

It’s easy to see how: Consider the four lines , , , and what we want is the hypothesis .

The corresponding MLP:

Next I’ll try to construct a cooler shape:

Now consider the three lines , and and we want . It looks like what’s left is to combine and into , however in such case the the number of layers we used is , which exceeds . I think we can simplify a little bit:

So the 3-layer perceptron in question is: