Comment by godelski

I disagree and even think that this is besides the point. It is hard to wonder about what you don't know to wonder about. It is the job of the communicator to prime that and provide any critical information that the reader is not expected to know about. Without some basic explanation here then these terms might as well be black boxes to readers.

The point is that a single line[0] and a minimal graphic could substantially improve the reader's comprehension while simultaneously providing them the necessary nomenclature to find relevant material to further increase their understanding.

Look at this line:

  | One of the most important classes goes by the humble name “P.” 

It tells us almost nothing, except of its importance. Only to be followed by

  | Roughly speaking, it encompasses all problems that can be solved in a reasonable amount of time. An analogous complexity class for space is dubbed “PSPACE.”

This tells us nothing... My first thought would by "why not PTIME and PSPACE" if I didn't already know what was going on.

The whole work is about bridging these two concepts! How can we understand that if we don't know what we're building a bridge between? It's like reporting on a bridge being built connecting England and France but just calling it a bridge. Is it important? Sounds like it by the way they talk, but how can you even know the impact of such a thing when not given such critical context? You get tremendous amounts of additional context with the addition of so few words.