ELI5: Explain Like I'm 5

Hahn-Hellinger theorem

Okay kiddo, imagine you have some blocks that you want to put together to make a big tower. But you have to follow some rules: you can't have any gaps or overlaps between the blocks.

Now, let's say you have two piles of blocks that you want to put together into one big pile. The Hahn-Hellinger theorem says that you can always put them together without any gaps or overlaps as long as they don't have any blocks in common.

So it's kind of like if you have two groups of friends and you want to combine them into one big group. If there are no friends that belong to both groups, you can just put them together without any problems. But if there are some friends that belong to both groups, you have to be careful not to count them twice or leave them out.

The Hahn-Hellinger theorem helps mathematicians solve problems that involve combining different sets of things. Just like how you can combine blocks or friends, they can combine numbers or equations. And this theorem helps them do it without any mistakes!