It is probably not the case that Bernhard is a rhino. It is certain that John went to the garden. We doubt that Greg is a swan.
Chances are about even that bernhard is a rhino, or Greg is a swan.
Chances are about even that bernhard is a rhino, or Greg is a swan.
It is impossible that bernhard is a rhino, or Greg is a swan.
Bernhard is a rhino, or Greg is a swan.