diff --git a/RACK-Ontology/OwlModels/GeneratePropInfoCSV.owl b/RACK-Ontology/OwlModels/GeneratePropInfoCSV.owl
index 6b487177..0fef3c54 100644
--- a/RACK-Ontology/OwlModels/GeneratePropInfoCSV.owl
+++ b/RACK-Ontology/OwlModels/GeneratePropInfoCSV.owl
@@ -1,7 +1,7 @@
 <rdf:RDF
     xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
+    xmlns:Ag="http://arcos.rack/AGENTS#"
     xmlns:builtinfunctions="http://sadl.org/builtinfunctions#"
-    xmlns:AGENTS="http://arcos.rack/AGENTS#"
     xmlns:CONFIDENCE="http://arcos.rack/CONFIDENCE#"
     xmlns:Pr="http://arcos.rack/PROCESS#"
     xmlns:sadlimplicitmodel="http://sadl.org/sadlimplicitmodel#"
diff --git a/RACK-Ontology/OwlModels/SYSTEM.owl b/RACK-Ontology/OwlModels/SYSTEM.owl
index 0342ad71..c3bb78dc 100644
--- a/RACK-Ontology/OwlModels/SYSTEM.owl
+++ b/RACK-Ontology/OwlModels/SYSTEM.owl
@@ -90,9 +90,7 @@
   </owl:ObjectProperty>
   <owl:ObjectProperty rdf:ID="source">
     <rdfs:subPropertyOf rdf:resource="PROV-S#wasImpactedBy"/>
-    <owl:inverseOf>
-      <owl:ObjectProperty rdf:ID="destination"/>
-    </owl:inverseOf>
+    <owl:inverseOf rdf:resource="#provides"/>
     <rdfs:comment xml:lang="en">SYSTEM that provides what the INTERFACE offers</rdfs:comment>
     <rdfs:range rdf:resource="#SYSTEM"/>
     <rdfs:domain rdf:resource="#INTERFACE"/>
@@ -124,9 +122,9 @@
     <rdfs:range rdf:resource="PROV-S#ACTIVITY"/>
     <rdfs:domain rdf:resource="#INTERFACE"/>
   </owl:ObjectProperty>
-  <owl:ObjectProperty rdf:about="#destination">
+  <owl:ObjectProperty rdf:ID="destination">
     <rdfs:subPropertyOf rdf:resource="PROV-S#wasImpactedBy"/>
-    <owl:inverseOf rdf:resource="#source"/>
+    <owl:inverseOf rdf:resource="#requires"/>
     <rdfs:comment xml:lang="en">SYSTEM that requires what the INTERFACE offers</rdfs:comment>
     <rdfs:range rdf:resource="#SYSTEM"/>
     <rdfs:domain rdf:resource="#INTERFACE"/>
diff --git a/RACK-Ontology/ontology/SYSTEM.sadl b/RACK-Ontology/ontology/SYSTEM.sadl
index 57d9ce4a..148ab576 100644
--- a/RACK-Ontology/ontology/SYSTEM.sadl
+++ b/RACK-Ontology/ontology/SYSTEM.sadl
@@ -46,11 +46,11 @@ INTERFACE
 	commodity describes INTERFACE with at most 1 value.
 
 	source (note "SYSTEM that provides what the INTERFACE offers") describes INTERFACE with values of type SYSTEM.
-	source is the inverse of destination.
+	source is the inverse of provides.
 	source is a type of wasImpactedBy.
 
 	destination (note "SYSTEM that requires what the INTERFACE offers") describes INTERFACE with values of type SYSTEM.
-	destination is the inverse of source.
+	destination is the inverse of requires.
 	destination is a type of wasImpactedBy.
 
 	identifiedBy (note "ACTIVITY out of which this INTERFACE was identified") describes INTERFACE with values of type ACTIVITY.