What is a base URI for a hosted turtle document containing <> but no defined base?

To answer this question:

https://www.w3.org/2000/10/swap/Primer.html

"The <> being an empty URI reference always refers to the document it is written in." I am guessing a document base URI becomes whatever URI the triples are hosted at. (the absolute URI).

Further exploration of <> went here. It talks about <> referring to a base URI.

https://www.w3.org/TeamSubmission/n3/ 

https://www.ietf.org/rfc/rfc3986.txt

"

5.1.3.  Base URI from the Retrieval URI

   If no base URI is embedded and the representation is not encapsulated
   within some other entity, then, if a URI was used to retrieve the
   representation, that URI shall be considered the base URI.  Note that
   if the retrieval was the result of a redirected request, the last URI
   used (i.e., the URI that resulted in the actual retrieval of the
   representation) is the base URI."