Lovely article about a simple technique that can be used to prevent a lots of bugs, and assist in the generation of correct code. Interesting that his code sti

Lovely article about a simple technique that can be used to prevent a lots of bugs, and assist in the generation of correct code. Interesting that his code still has a (probably never triggered) bug. EDIT: Actually, looking at the exchange in the comments, the bug I thought it has, isn't. The code is right, but for a subtle (to me) reason that isn't clear (to me) from any of the comments, the code, or the invariant. Even more interesting than I thought.