context: Skateboarder jumps off a 5 ft cliff, performing a stunt.
hypothesis: There is little chance that a skateboarder is about to fall off his skateboard.
valid_hypothesis: There is little chance that a skateboarder is about to fall off his skateboard.
invalid_hypothesis: It is almost certain that a skateboarder is about to fall off his skateboard.
hypothesis_assertion: A skateboarder is about to fall off his skateboard.