diff --git a/examples/COVIDCase.ttl b/examples/COVIDCase.ttl
index 9feb09a51067beecdabca7afb363c55de674b69c..c732b410f4ab93ef97ba4700d94b2d3f049d0cf7 100644
--- a/examples/COVIDCase.ttl
+++ b/examples/COVIDCase.ttl
@@ -11,6 +11,7 @@
 @prefix s4ehaw: <https://saref.etsi.org/saref4ehaw/> .
 @prefix s4envi: <https://saref.etsi.org/saref4envi/> .
 @prefix s4wear: <https://saref.etsi.org/saref4wear/> .
+@prefix ssn-system: <http://www.w3.org/ns/ssn/systems/> .
 @prefix dcterms: <http://purl.org/dc/terms/> .
 @base <https://saref.etsi.org/saref4ehaw/examples/COVIDCase/> .
 
@@ -70,7 +71,7 @@ s4ehawInst:BobAndroidphone rdf:type owl:NamedIndividual ,
 ###  https://saref.etsi.org/saref4ehaw/examples/COVIDCase/BobBodyTemp1
 s4ehawInst:BobBodyTemp1 rdf:type owl:NamedIndividual ,
                                  saref:Measurement ;
-                                 s4ehaw:hasValues "39"^^xsd:int .
+                                 saref:hasValue "39"^^xsd:int .
 
 
 ###  https://saref.etsi.org/saref4ehaw/examples/COVIDCase/BobBodyThermo
@@ -99,7 +100,7 @@ s4ehawInst:BobMonitorBan rdf:type owl:NamedIndividual ,
 ###  https://saref.etsi.org/saref4ehaw/examples/COVIDCase/BobRespMeas1
 s4ehawInst:BobRespMeas1 rdf:type owl:NamedIndividual ,
                                  saref:Measurement ;
-                                 s4ehaw:hasValues "22"^^xsd:int .
+                                 saref:hasValue "22"^^xsd:int .
 
 
 ###  https://saref.etsi.org/saref4ehaw/examples/COVIDCase/BobScanWatch
@@ -165,13 +166,13 @@ s4ehawInst:BobSpireVibro rdf:type owl:NamedIndividual ,
 ###  https://saref.etsi.org/saref4ehaw/examples/COVIDCase/BobSpo2Lev1
 s4ehawInst:BobSpo2Lev1 rdf:type owl:NamedIndividual ,
                                 saref:Measurement ;
-                                s4ehaw:hasValues "78.0"^^xsd:double .
+                                saref:hasValue "78.0"^^xsd:double .
 
 
 ###  https://saref.etsi.org/saref4ehaw/examples/COVIDCase/BobSystolicPressure
 s4ehawInst:BobSystolicPressure rdf:type owl:NamedIndividual ,
                                         saref:Measurement ;
-                                        s4ehaw:hasValues "75"^^xsd:int .
+                                        saref:hasValue "75"^^xsd:int .
 
 
 ###  https://saref.etsi.org/saref4ehaw/examples/COVIDCase/BodyTemperature
@@ -465,7 +466,7 @@ s4ehaw:MmHG rdf:type owl:NamedIndividual ,
                                                                                                                        ] ;
                                                                                                              rdf:rest [ rdf:type <http://www.w3.org/2003/11/swrl#AtomList> ;
                                                                                                                         rdf:first [ rdf:type <http://www.w3.org/2003/11/swrl#DatavaluedPropertyAtom> ;
-                                                                                                                                    <http://www.w3.org/2003/11/swrl#propertyPredicate> s4ehaw:hasValues ;
+                                                                                                                                    <http://www.w3.org/2003/11/swrl#propertyPredicate> saref:hasValue ;
                                                                                                                                     <http://www.w3.org/2003/11/swrl#argument1> <urn:swrl:var#meas2> ;
                                                                                                                                     <http://www.w3.org/2003/11/swrl#argument2> <urn:swrl:var#val2>
                                                                                                                                   ] ;
@@ -493,7 +494,7 @@ s4ehaw:MmHG rdf:type owl:NamedIndividual ,
                                                                                                                                                                    ] ;
                                                                                                                                                          rdf:rest [ rdf:type <http://www.w3.org/2003/11/swrl#AtomList> ;
                                                                                                                                                                     rdf:first [ rdf:type <http://www.w3.org/2003/11/swrl#DatavaluedPropertyAtom> ;
-                                                                                                                                                                                <http://www.w3.org/2003/11/swrl#propertyPredicate> s4ehaw:hasValues ;
+                                                                                                                                                                                <http://www.w3.org/2003/11/swrl#propertyPredicate> saref:hasValue ;
                                                                                                                                                                                 <http://www.w3.org/2003/11/swrl#argument1> <urn:swrl:var#meas> ;
                                                                                                                                                                                 <http://www.w3.org/2003/11/swrl#argument2> <urn:swrl:var#val>
                                                                                                                                                                               ] ;
@@ -544,7 +545,7 @@ s4ehaw:MmHG rdf:type owl:NamedIndividual ,
                                                                                                                                                                                                                                                                       ] ;
                                                                                                                                                                                                                                                             rdf:rest [ rdf:type <http://www.w3.org/2003/11/swrl#AtomList> ;
                                                                                                                                                                                                                                                                        rdf:first [ rdf:type <http://www.w3.org/2003/11/swrl#DatavaluedPropertyAtom> ;
-                                                                                                                                                                                                                                                                                   <http://www.w3.org/2003/11/swrl#propertyPredicate> s4ehaw:hasValues ;
+                                                                                                                                                                                                                                                                                   <http://www.w3.org/2003/11/swrl#propertyPredicate> saref:hasValue ;
                                                                                                                                                                                                                                                                                    <http://www.w3.org/2003/11/swrl#argument1> <urn:swrl:var#meas1> ;
                                                                                                                                                                                                                                                                                    <http://www.w3.org/2003/11/swrl#argument2> <urn:swrl:var#val1>
                                                                                                                                                                                                                                                                                  ] ;
@@ -656,7 +657,7 @@ s4ehaw:MmHG rdf:type owl:NamedIndividual ,
                                                                                                             ] ;
                                                                                                   rdf:rest [ rdf:type <http://www.w3.org/2003/11/swrl#AtomList> ;
                                                                                                              rdf:first [ rdf:type <http://www.w3.org/2003/11/swrl#DatavaluedPropertyAtom> ;
-                                                                                                                         <http://www.w3.org/2003/11/swrl#propertyPredicate> s4ehaw:hasValues ;
+                                                                                                                         <http://www.w3.org/2003/11/swrl#propertyPredicate> saref:hasValue ;
                                                                                                                          <http://www.w3.org/2003/11/swrl#argument1> <urn:swrl:var#meas> ;
                                                                                                                          <http://www.w3.org/2003/11/swrl#argument2> <urn:swrl:var#val>
                                                                                                                        ] ;
@@ -702,7 +703,7 @@ s4ehaw:MmHG rdf:type owl:NamedIndividual ,
                                                                                                                                                                                          ] ;
                                                                                                                                                                                rdf:rest [ rdf:type <http://www.w3.org/2003/11/swrl#AtomList> ;
                                                                                                                                                                                           rdf:first [ rdf:type <http://www.w3.org/2003/11/swrl#DatavaluedPropertyAtom> ;
-                                                                                                                                                                                                      <http://www.w3.org/2003/11/swrl#propertyPredicate> s4ehaw:hasValues ;
+                                                                                                                                                                                                      <http://www.w3.org/2003/11/swrl#propertyPredicate> saref:hasValue ;
                                                                                                                                                                                                       <http://www.w3.org/2003/11/swrl#argument1> <urn:swrl:var#meas1> ;
                                                                                                                                                                                                       <http://www.w3.org/2003/11/swrl#argument2> <urn:swrl:var#val1>
                                                                                                                                                                                                     ] ;