Assertion: grandmother's father | /r/HasProperty | sibling
Facets:
Source sentences:
text: They are 1st cousins, since his mother (2F-Davis) and her father (2M-Davis) are siblings.
text: In this case, it just so happens that both "other sides" are the same for those two sets of cousins, since the father of your cousins and the mother of your girlfriend's cousins are siblings.