skos/commit

FIXED: make json_all_literal_propvalues/3 check if found literal is really a literal

diff --git a/lib/skos/json.pl b/lib/skos/json.pl
index 4f53a59..69fb1f0 100644
--- a/lib/skos/json.pl
+++ b/lib/skos/json.pl
@@ -14,6 +14,7 @@
 json_all_literal_propvalues(R,P,Definitions) :-
 	findall(Lang-Definition,
 		(   rdf_has(R, P, DefLit),
+		    rdf_is_literal(DefLit),
 		    literal_text(DefLit,Definition),
 		    (	DefLit = literal(lang(Lang, _))
 		    ->	true