The paper is hard to read. There is no concrete worked-through example, the prose is over the top, and the equations don't really help. I can't make head or tail of this paper.
This appears to be a position paper written by authors outside of their core field. The presentation of "the wall" is only through analogy to derivatives on the discrete values computer's operate in.
If you look at their other papers, you will see that this is very much within their core field.