context: It is almost certain that Gertrude is a mouse. It is certain that John picked up the milk. Chances are about even that Bernhard is a lion. It is highly unlikely that if either Gertrude is a mouse, or Bernhard is a lion, then Julius is a frog. There is a better than even chance that if either Bernhard is a lion, or Gertrude is a mouse, then Winona is a wolf. It is probably the case that if John picked up the milk, or Gertrude is a mouse, then Lily is white.
hypothesis: It is probable that either Julius is a frog, or Lily is white.
valid_hypothesis: It is probable that either Julius is a frog, or Lily is white.
invalid_hypothesis: We doubt that either Julius is a frog, or Lily is white.
hypothesis_assertion: Either Julius is a frog, or Lily is white.