As I said in another comment[1], I'm not even talking about software engineering, just a good practices of everyday programming. Could you please tell me why d

As I said in another comment[1], I'm not even talking about software engineering, just a good practices of everyday programming. Could you please tell me why do you think that the name `x` is better than `element` (when talking about some set), the name `X` is better than `training_set`, and the `∑` is better than `sum`? [1] Here: https://news.ycombinator.com/item?id=15914024 https://news.ycombinator.com/item?id=15914024