:- use_module(library(semweb/rdf_db)). [nondet]rdf_current_predicate(?Predicate)
[nondet]rdf_current_predicate(?Predicate)
Note that resources that have rdf:type rdf:Property 
are not automatically included in the result-set of this predicate, 
while all resources that appear as the second argument of a 
triple are included.