This diagram concludes that the student at position 0 will never go through the doorway at position 1.
There is a story of an eccentric math teacher who claimed that once in his classroom his students would never be able to leave. When asked why, he responded: ‘Before you can go through the doorway you must first go halfway. Once you get halfway, you must once again go halfway to the doorway, and so on ad infinitum. Thus, once you are in my classroom you will never be able leave!’ Discuss the logic behind the story and the paradoxical nature of actually being able to exit the classroom. This is based on Zeno’s paradox.