amalgame/commit

ADDED: collect reference alignments from multiple graphs that are marked as amalgame:reference in the given Strategy

diff --git a/lib/amalgame/ag_reference.pl b/lib/amalgame/ag_reference.pl
new file mode 100644
index 0000000..c184262
--- /dev/null
+++ b/lib/amalgame/ag_reference.pl
@@ -0,0 +1,18 @@
+:- module(ag_reference,
+	  [ reference_mappings/2
+	  ]).
+
+:- use_module(library(apply)).
+:- use_module(library(lists)).
+:- use_module(library(semweb/rdf_db)).
+:- use_module(library(amalgame/expand_graph)).
+
+%%	reference_mappings(+Strategy, -References) is det.
+%
+%	Reference contains all reference (ground truth) correspondences
+%	for Strategy or the empty list if no refs are available.
+
+reference_mappings(Strategy, References) :-
+	findall(R, rdf(R, amalgame:status, amalgame:reference, Strategy), RefGraphs),
+	maplist(expand_node(Strategy), RefGraphs, MappingLists),
+	append(MappingLists, References).