Some searching found http://logitext.mit.edu/tutorial http://logitext.mit.edu/tutorial . It tries to explain sequent calculus with an interactive gui prover. No

Some searching found http://logitext.mit.edu/tutorial http://logitext.mit.edu/tutorial . It tries to explain sequent calculus with an interactive gui prover. Not sure how approachable it is... I've gotten too used to these things to know how to explain them properly.