rdf* to rdf

a.ttl

@prefix ex:    <http://example/> .

ex:s    ex:p    ex:o .

[ a       <http://www.w3.org/1999/02/22-rdf-syntax-ns#Statement> ;
  <http://www.w3.org/1999/02/22-rdf-syntax-ns#object>
          ex:o ;
  <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate>
          ex:p ;
  <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject>
          ex:s ;
  ex:q    ex:z
] .

a.ttls

@prefix ex: <http://example/> .

ex:s ex:p ex:o .
<<ex:s ex:p ex:o>> ex:q ex:z .

a.txt

"On one hand, RDF* and SPARQL* may be understood–and used–simply as syntactic sugar on top of RDF and SPARQL. 
That is, any RDF*-specific syntax such as Turtle* may be parsed directly into plain RDF data that uses RDF 
reification or any of the other approaches to annotate statements in RDF. Likewise, SPARQL* queries may be 
rewritten into ordinary SPARQL queries."

https://blog.liu.se/olafhartig/2019/01/10/position-statement-rdf-star-and-sparql-star/