But now we can just write the probability that capital Y is less than or equal to 30. It's a little bit cleaner notation. And if someone else cares about the probability that the sum of the upward face after rolling 7 dice, if they say, hey, what's the probability that that's even, instead of having to write all of that over, they can say, well, what's the probability that Y is even? Now, the one thing that I do want to emphasize is how these are different than traditional variables, traditional variables that you see in your algebra class, like x plus 5 is equal to 6, usually denoted by lowercase variables. Y is equal to x plus 7. These variables, you can essentially assign values. You either can solve for them.