There is little chance that John discarded the milk. We doubt that Brian is a swan. There is little chance that Julius is a rhino.
It is highly likely that either John discarded the milk, or Brian is a swan.
It is probably not the case that either John discarded the milk, or Brian is a swan.
It is highly likely that either John discarded the milk, or Brian is a swan.
Either John discarded the milk, or Brian is a swan.