To further expand on the "a few simple formulae", many of those experienced in these fields will note that complexity can emerge from simplicity. Conway's Game

To further expand on the "a few simple formulae", many of those experienced in these fields will note that complexity can emerge from simplicity. Conway's Game of Life is my go to example. Following some of about the simplest rules you can have, you can create a fully Turing complete system able to emulate itself.