A demonstration that greater than human intelligence is possible is that there are now computer-generated mathematical proofs that are true that no human can understand. No, the computer does not “understand” it either in the sense that we mean here, but it’s not clear what sense we mean, exactly.
I had a friend who could work out mathematical equations expertly, but didn’t understand really any of what they meant, while I could understand their implications but could not work them out. Who here comprehended those equations better? That’s a question I cannot honestly answer perhaps because the answer is extremely contingent or because that it is the wrong question altogether.