premise1: A young man attempts to ride a unicycle down an outdoor stairway stained with moss.
premise2: The man is pedaling the tiny bike down the steps.
premise3: A man skates down a long outdoor stairway.
premise4: A guy riding something down steps.
premise: A young man attempts to ride a unicycle down an outdoor stairway stained with moss. The man is pedaling the tiny bike down the steps. A man skates down a long outdoor stairway. A guy riding something down steps.
hypothesis: A man flies on a skateboard.