 [nondet]rdf_current_prefix(:Alias, 
?URI)Query predefined prefixes and prefixes defined with
rdf_register_prefix/2 
and local prefixes defined with
rdf_prefix/2. If Alias is 
unbound and one URI is the prefix of another, the longest is 
returned first. This allows turning a resource into a prefix/local 
couple using the simple enumeration below. See rdf_global_id/2.
[nondet]rdf_current_prefix(:Alias, 
?URI)Query predefined prefixes and prefixes defined with
rdf_register_prefix/2 
and local prefixes defined with
rdf_prefix/2. If Alias is 
unbound and one URI is the prefix of another, the longest is 
returned first. This allows turning a resource into a prefix/local 
couple using the simple enumeration below. See rdf_global_id/2.
rdf_current_prefix(Prefix, Expansion),
atom_concat(Expansion, Local, URI),