diff --git a/src/cco-extensions/ModalRelationOntology.ttl b/src/cco-extensions/ModalRelationOntology.ttl
index 64d0216..81d352c 100644
--- a/src/cco-extensions/ModalRelationOntology.ttl
+++ b/src/cco-extensions/ModalRelationOntology.ttl
@@ -388,7 +388,7 @@ mro:BFO_0000153 rdf:type owl:ObjectProperty ;
                 rdfs:range obo:BFO_0000008 ;
                 <http://purl.org/dc/elements/1.1/identifier> "080-BFO" ;
                 rdfs:label "temporally projects onto"@en ;
-                <http://www.w3.org/2004/02/skos/core#definition> "(Elucidation) temporally projects onto is a relation between a spatiotemporal region s and some temporal region which is the temporal extent of s"@en ;
+                <http://www.w3.org/2004/02/skos/core#definition> "x temporally_projects_onto y iff x is an instance of Spatiotemporal Region and y is an instance of Temporal Region and y is the temporal extent of x."@en ;
                 <http://www.w3.org/2004/02/skos/core#example> "The world line of a particle temporally projects onto the temporal region extending from the beginning to the end of the existence of the particle"@en .