:- use_module(library(semweb/turtle)). [det]rdf_save_turtle(+Out, 
:Options)
[det]rdf_save_turtle(+Out, 
:Options)true (default), use a for the predicate rdf:type. 
Otherwise use the full resource.true (default false), emit numeric 
datatypes using Prolog's write to achieve canonical output.true (default), write some informative comments between 
the output segmentstrue (default), using P-O and O-grouping.true (default), inline bnodes that are used once.true (default), omit the type if allowed by turtle.true (default false), do not print the 
final informational message.true (default false), write [...] and (...) 
on a single line.true (default), use prefixes from rdf_current_prefix/2.
The option expand allows for serializing alternative 
graph representations. It is called through call/5, 
where the first argument is the expand-option, followed by S,P,O,G. G is 
the graph-option (which is by default a variable). This notably allows 
for writing RDF graphs represented as rdf(S,P,O) using the 
following code fragment:
triple_in(RDF, S,P,O,_G) :-
    member(rdf(S,P,O), RDF).
    ...,
    rdf_save_turtle(Out, [ expand(triple_in(RDF)) ]),
| Out | is one of stream(Stream), a 
stream handle, a file-URL or an atom that denotes a filename. |