Entry tags:
Small Step Semantics for Python
As I've commented before, I don't like Python, this paper shows off a couple reasons why. (Equations strictly optional).
http://cs.brown.edu/~sk/Publications/Papers/Published/pmmwplck-python-full-monty/paper.pdf
http://cs.brown.edu/~sk/Publications/Papers/Published/pmmwplck-python-full-monty/paper.pdf