diff --git a/src/cco-imports/bfo-core.ttl b/src/cco-imports/bfo-core.ttl
index c3fc163..116d602 100644
--- a/src/cco-imports/bfo-core.ttl
+++ b/src/cco-imports/bfo-core.ttl
@@ -391,7 +391,7 @@ skos:scopeNote rdf:type owl:AnnotationProperty .
                                              rdfs:range <http://purl.obolibrary.org/obo/BFO_0000008> ;
                                              dc11:identifier "080-BFO" ;
                                              rdfs:label "temporally projects onto"@en ;
-                                             skos: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 ;
+                                             skos: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 ;
                                              skos: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 .