Strong subadditivity
Okay kiddo, so imagine you have a big box of toys. You have some blocks, some dolls, and some cars. You also have two smaller boxes, one that has blocks and dolls, and the other that has dolls and cars.
Now, let's say you want to know how many toys you have in total. One way to do that is to add up the number of toys in each box and then add those two numbers together. But there's another way to figure it out.
You could also count the toys in the big box first. Then, you could count the toys in the box with blocks and dolls, and add that number to the number of toys in the box with dolls and cars.
No matter which way you do it, you should end up with the same answer, right? Well, that's what strong subadditivity is all about. It says that if you have three different things (in this case, the big box and the two smaller boxes), then the total number of toys you have should always be less than or equal to the sum of the number of toys in each of those things individually.
Basically, it's all about making sure you don't double-count any toys or count any toys more than once. So you can count the toys in different boxes however you like -- you can count them one box at a time or all together -- and you should always end up with the same answer, as long as you don't count any toys twice.
So there you have it, kiddo. Strong subadditivity is like making sure you don't count the same toy twice when you're trying to figure out how many toys you have in total.
Now, let's say you want to know how many toys you have in total. One way to do that is to add up the number of toys in each box and then add those two numbers together. But there's another way to figure it out.
You could also count the toys in the big box first. Then, you could count the toys in the box with blocks and dolls, and add that number to the number of toys in the box with dolls and cars.
No matter which way you do it, you should end up with the same answer, right? Well, that's what strong subadditivity is all about. It says that if you have three different things (in this case, the big box and the two smaller boxes), then the total number of toys you have should always be less than or equal to the sum of the number of toys in each of those things individually.
Basically, it's all about making sure you don't double-count any toys or count any toys more than once. So you can count the toys in different boxes however you like -- you can count them one box at a time or all together -- and you should always end up with the same answer, as long as you don't count any toys twice.
So there you have it, kiddo. Strong subadditivity is like making sure you don't count the same toy twice when you're trying to figure out how many toys you have in total.