adding alternative RDF TriG syntax example

README.md

@@ -10,3 +10,40 @@ See the living document [RDF Surfaces Primer](https://w3c-cg.github.io/rdfsurfac
 
 - https://github.com/eyereasoner/Notation3-By-Example/tree/main/blogic
 - https://github.com/eyereasoner/eye/tree/b81e05163e21e93e9fc0ab27c369af7f98a16658/reasoning/blogic
+
+### Example using alternative RDF TriG syntax
+
+```trig
+# ------------------
+# Socrates inference
+# ------------------
+#
+# Infer that Socrates is mortal.
+
+@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#>.
+@prefix blogic: <http://www.w3.org/2000/10/swap/blogic#>.
+@prefix : <http://example.org/ns#>.
+
+:Socrates a :Man.
+:Man rdfs:subClassOf :Human.
+:Human rdfs:subClassOf :Mortal.
+
+(_:A _:B _:S) blogic:onNegativeSurface _:subclass_surface1.
+
+_:subclass_surface1 {
+    _:A rdfs:subClassOf _:B.
+    _:S a _:A.
+    () blogic:onNegativeSurface _:subclass_surface2.
+}
+
+_:subclass_surface2 {
+    _:S a _:B.
+}
+
+# query
+(_:S _:C) blogic:onQuerySurface _:query_surface.
+
+_:query_surface {
+    _:S a _:C.
+}
+```