context: It is impossible that John discarded the apple. Chances are slight that Gertrude is a mouse. There is a very good chance that Bernhard is a frog. There is a very good chance that if either Bernhard is a frog, or John discarded the apple, then Bill went to the office. We doubt that if either Bernhard is a frog, or John discarded the apple, then Fred left the football. It is unlikely that if John discarded the apple, or Gertrude is a mouse, then Greg is yellow.
hypothesis: We believe that gertrude is a mouse, or Fred left the football.
valid_hypothesis: It is probably not the case that gertrude is a mouse, or Fred left the football.
invalid_hypothesis: We believe that gertrude is a mouse, or Fred left the football.
hypothesis_assertion: Gertrude is a mouse, or Fred left the football.