context: It is impossible that Bernhard is a frog. Chances are slight that John left the apple. There is a better than even chance that Emily is a mouse. There is a very good chance that if John left the apple, and Bernhard is a frog, then Sandra grabbed the milk. We doubt that if either Emily is a mouse, or John left the apple, then Brian is a swan. We doubt that if either Bernhard is a frog, or Emily is a mouse, then Greg is a rhino.
hypothesis: We believe that greg is a rhino, and Brian is a swan.
valid_hypothesis: There is almost no chance that greg is a rhino, and Brian is a swan.
invalid_hypothesis: We believe that greg is a rhino, and Brian is a swan.
hypothesis_assertion: Greg is a rhino, and Brian is a swan.