Note the conceptual difference between programs that produce many pages of output (and it may happen to be just one), and programs that produce just one piece of graphics; a “book” with just one page is still a book, and hence not something which should be included on a page of another document. If the output is something to be placed on a page of an external document, then there is only one logical page to paint, namely •page.

Most Shapes core states represent various aspects of the changing world outside a Shapes program, and have to be provided in the initial environment since they cannot be spawned deterministically from a hot value. On the other hand, •page (and •catalog) can be replaced by user-defined states, but are provided to make a Shapes program easier to read, as not every user will have to invent its own name for a state with the same purpose.