context: Several people are wading in a river in a deep gorge.
hypothesis: It is highly unlikely that several people are wading ina  dangerous river that may cost them their lives.
valid_hypothesis: It is highly unlikely that several people are wading ina  dangerous river that may cost them their lives.
invalid_hypothesis: Chances are about even that several people are wading ina  dangerous river that may cost them their lives.
hypothesis_assertion: Several people are wading ina  dangerous river that may cost them their lives.