context: The firefighter has a hose ready to tackle a car fire.
hypothesis: Chances are about even that a male firefighter checks his hose before using it.
valid_hypothesis: Chances are about even that a male firefighter checks his hose before using it.
invalid_hypothesis: It is highly unlikely that a male firefighter checks his hose before using it.
hypothesis_assertion: A male firefighter checks his hose before using it.