rdf_qa/commit

pred only heuristic

diff --git a/components/qa_default_heuristics.pl b/components/qa_default_heuristics.pl
index 71bd0b5..5ed103d 100644
--- a/components/qa_default_heuristics.pl
+++ b/components/qa_default_heuristics.pl
@@ -3,4 +3,6 @@
 :- use_module(qa_cycle_prop).
 :- use_module(qa_empty_repo).
 :- use_module(qa_object_only).
+:- use_module(qa_pred_only).
 :- use_module(qa_no_label).
+:- use_module(qa_domain_whitelist).
diff --git a/components/qa_pred_only.pl b/components/qa_pred_only.pl
new file mode 100644
index 0000000..17df431
--- /dev/null
+++ b/components/qa_pred_only.pl
@@ -0,0 +1,14 @@
+:- module(qa_predicate, []).
+
+:- use_module(qa_heuristics).
+:- use_module(library(semweb/rdf_db)).
+:- use_module(library(http/html_write)).
+
+
+qa:rdf_warning(pred_only, rdf(S,P,O)) :-
+	rdf_current_predicate(P),
+        \+ rdf_subject(P),
+	\+ qa:rdf_qa_ok(pred_only, P),
+	rdf(S,P,O).
+qa:class_label(pred_only) -->
+        html(['Triples with ', i('Predicate that is never a Subject')]).