A group of writers and mathematicians formed a group called Oulipo (Ouvroir de littérature potentielle). They saught to create works using constrained writing techniques. Italo Calvino was a member of this group and used the book If on a Winter’s Night a Traveler as an Oulipo experiment.
Bring order and logic into a book that, upon first glance, seems to be arbitrary by borrowing the visual language of maps.
For instance, the above square translates into:
The living reader <R> reads
the physical book <B>
The physical book <B> tells
the story of the reader who is
in the book <r>
The reader who is in the book
does not arrive to read the book, which is in the book <b>