Sort numbers using only 2 hidden layers I'm reading the cornerstone paper Sequence to Sequence Learning
with Neural Networks by Ilya Sutskever and Quoc Le. On the first page, it briefly mentions that: 

A surprising example of the power of DNNs is their ability to sort
N N-bit numbers using only 2 hidden layers of quadratic size 


Can anyone briefly outline how to sort numbers using only 2 hidden layers?
Doing some research, I found a paper which proves that sorting can be done with at most 3 layers, and that their solution is optimal if you restrict the size of the network to be polynomial w.r.t. to the number of input numbers:

Depth Efficient Neural Networks for Division and Related Problems, see Theorem 7 on page 955 (page 10 in the PDF).