From dbc62d5561868680136fac603ff8bd04ca0774ee Mon Sep 17 00:00:00 2001
From: Egon Willighagen <egon.willighagen@gmail.com>
Date: Sun, 25 Oct 2020 21:07:30 +0100
Subject: [PATCH] Only handle upper OWL classes

---
 src/main/java/com/github/enanomapper/Slimmer.java | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/src/main/java/com/github/enanomapper/Slimmer.java b/src/main/java/com/github/enanomapper/Slimmer.java
index 28eb247..43d6d5c 100644
--- a/src/main/java/com/github/enanomapper/Slimmer.java
+++ b/src/main/java/com/github/enanomapper/Slimmer.java
@@ -466,11 +466,13 @@ private Set<String> allSuperClasses(OWLClass clazz,
 		Set<String> allSuperClasses = new HashSet<String>();
 		Stream<OWLClassExpression> superClasses = Searcher.sup(onto.subClassAxiomsForSubClass(clazz));
 		superClasses.forEach(superClass -> {
-			OWLClass superOwlClass = superClass.asOWLClass();
-			String superIri = superOwlClass.getIRI().toString();
-			allSuperClasses.add(superIri);
-			// recurse
-			allSuperClasses.addAll(allSuperClasses(superOwlClass, onto));
+			if (superClass.isOWLClass()) {
+				OWLClass superOwlClass = superClass.asOWLClass();
+				String superIri = superOwlClass.getIRI().toString();
+				allSuperClasses.add(superIri);
+				// recurse
+				allSuperClasses.addAll(allSuperClasses(superOwlClass, onto));
+			}
 		});
 		return allSuperClasses;
 	}
@@ -517,4 +519,4 @@ private void addMappings(OWLOntologyManager m, String root) {
 		}
 	}
 
-}
\ No newline at end of file
+}