A man in a green sheet is in midair on a green-wheeled skateboard at a skateboard park .
A man in green is skateboarding .
A man in a green sheet is in midair on a green-wheeled skateboard at a skateboard park.
A man in green is skateboarding.
If he is on a skateboard, it follows that he is skateboarding.
If he is on a skateboard , it follows that he is skateboarding .