Presumably this was converted from markdown or similar and the conversion partly failed or the input was broken. From the PVI section onward it seems to recove

Presumably this was converted from markdown or similar and the conversion partly failed or the input was broken. From the PVI section onward it seems to recover, but if the author sees this please fix and re-convert your post. [Edited, nope, there are more errors further in the text, this needed proper proofreading before it was posted, I can somewhat struggle through because I already know this topic but if this was intended to introduce newcomers it's probably very confusing]