Running the code: Just run “lein repl” from the project root. That will drop you into an environment where all the mathematical overloads have been set up to begin working with examples from the book or creating your own.
Note that if you run under CIDER, there are some REPL hacks that aren’t installed (algebraic simplification and pretty printing are handled as middleware): to get around that you can wrap expressions in (print-expression).
Feynman on the Principle of Least Action
First demo: The Double Pendulum.
Second demo (if time permits): The Driven Pendulum with Surfaces of Section.