It is certain that John left the apple. We doubt that Lily is green. There is almost no chance that Brian is a lion. It is probably the case that if John left the apple, and Lily is green, then Greg is a frog. Chances are about even that if Lily is green, and Brian is a lion, then Julius is gray. There is little chance that if Lily is green, or Brian is a lion, then Jessica is a sheep.
We doubt that either Julius is gray, or Lily is green.
We doubt that either Julius is gray, or Lily is green.
It is probable that either Julius is gray, or Lily is green.
Either Julius is gray, or Lily is green.