If all X belongs to A, it can be inferred that X belongs to B (which means A is a part of B, but I don't know if A is all of B).

And there is x0 in B, it can be inferred that x0 also belongs to A (this part shows that there is x0 in B, and it also exists in A, and inverted E means existence, which means at least one, not all, and since it exists, then A is definitely not equal to B).

Then A belongs to but is not equal to B (if it is equal to B, then all the elements in B are in A, so they can't be said to exist, but they should all be said).