It is almost certain that John dropped the milk. It is highly unlikely that Julie is in the bedroom. It is highly likely that Jessica is a cat. It is improbable that if John dropped the milk, or Julie is in the bedroom, then Mary went to the office. Chances are slight that if Jessica is a cat, and Julie is in the bedroom, then Brian is a lion. It is unlikely that if Jessica is a cat, or John dropped the milk, then Greg is yellow.
We believe that either Greg is yellow, or John dropped the milk.
We believe that either Greg is yellow, or John dropped the milk.
There is little chance that either Greg is yellow, or John dropped the milk.
Either Greg is yellow, or John dropped the milk.