I know a lot of black hole questions have been posted, but these ones probably haven't arose before. I'd be gratefull for any responses. 1. Is it possible to have a black-hole 'inside a black-hole'? I ask this because there is mathematical evidence to suggest the Universe is a supermassive black-hole, in which case the black-holes we observe would have to exist 'inside' it. 2. If an observer was inside a black-hole, the Universe could not exist, from that observer. Correct? Thus on similar logic we can say a universe exists outside our own, but we would be unable to prove it. Finally, with regard to the accelerating Universe. Can we posit the Universe to undergo accelerating and decelerating expansion consecutively, so that one cancels out the other? This would make it so the Universe would eventually contract, fitting in with the idea of a closed black-hole.