> it's not movable
I don't know what to say here. This is obviously false. Why did you say this?
What do you think is the difference between a "book" and a "codex"? Why do you think ancient texts are divided into "books"?
According to wikipedia:
"The codex (pl.: codices /ˈkoʊdɪsiːz/)[1] was the historical ancestor format of the modern book. Technically the vast majority of modern books use the codex format of a stack of pages bound at one edge, along the side of the text. But the term "codex" is now reserved for older manuscript books, which mostly used sheets of vellum, parchment, or papyrus, rather than paper.[2] "
I would say a codex is a book yes, you are right there. The defining characteristic for me is the binding method, the flippable pages and the bookiness factor of the book.
That said, unbound scrolls that are scrolled into scrolls of scroll are definitely scrolls and not books.
So 2 to 1, gg.