Takes any algorithm that can generates the digits of pi. It is proven that all the sequences of digits are present somewhere in these digits. Can you claim copyright on all the books of the universe because you can show the algorithm that can generate every possible books ?

"It is proven that all the sequences of digits are present somewhere in these digits"

This has never been proven for the digits of π. Of course, there are other digit-sequences for which it is trivially true. For example, just concatenating together every finite sequence of digits, in some suitable order.

I stand corrected. For pi, it is only a conjecture. My point remains true for "Champernowne sequence".

Without being any kind of copyright expert, this argument doesn't make much sense. If you have the relevant indices into pi, I guess you could claim copyright. The index will be much larger than the original book though. Essentially you have a really bad compression algorithm. I'm not going to get very far claiming that because my decompression algorithm could output any sequence, all sequences are mine.

It has already been done (even though it is only a conjecture):

https://news.ycombinator.com/item?id=13869691

So in other words you need to have used the compressor to compress what you are copyrighting, and that which you used it on must have been physically stored in its entirety. Is it provable that this all occurred, if there's no requirement to still have the original? It would require that you also supply the compressor to the court, so that somebody can use your self-extracting magic decompressor, recompress the result, and end up back in the same place. But you could make your compressor simply emit your decompressor, ignoring the input!