For Mathematics, trees are more useful than strings. Professor Thorsten Altenkirch takes us through a functional approach to coding them in Python. Thorsten's Python programming book: https://bit.ly/2p3r5IT https://www.facebook.com/computerphile https://twitter.com/computer_phile This video was filmed and edited by Sean Riley. Computer Science at the University of Nottingham: https://bit.ly/nottscomputer Computerphile is a sister project to Brady Haran's Numberphile. More at http://www.bradyharan.com/