ELI5: Explain Like I'm 5

Partially ordered ring

Hey there kiddo! So you know what a ring is, right? It's like a special kind of number system where you can add, subtract, and multiply things. But a partially ordered ring is a little bit different.

So, let's start with what it means to be "partially ordered." Think of a bunch of toys on the floor in your room. You might say some toys are "bigger" than others, or some toys are "more important" than others. This is sort of like an order - we are ranking them by size or importance. But we might not be able to say that all toys are "bigger" or "more important" than each other - some things might be tied or equal. This is what it means for the ranking to be "partial" - it doesn't cover everything.

In a partially ordered ring, the ring is the same as before, but now the elements in the ring can be ranked or ordered in a partial way. Instead of saying that A is bigger than B, we say A is "greater than or equal to" B, or A >= B. This doesn't mean that A must always be bigger than B, though - they might be equal, or B might be greater than A, or they might not be related or comparable at all.

This partial ordering lets us talk about things like "upper bounds" - if we have a bunch of elements in the ring, an upper bound is an element that is greater than or equal to all the others. But we don't necessarily have a "greatest" or "biggest" element, because there might not be anything that is strictly greater than everything else.

Overall, a partially ordered ring is just a way of adding some structure and ranking to a normal ring, without having to impose a strict total order where everything is always bigger or smaller than something else.