A man in a wetsuit is surfing up and over a wave .
A man is skating on a half pipe .
A man in a wetsuit is surfing up and over a wave.
A man is skating on a half pipe.
If the man is surfing up and over a wave, then he cannot be skating on a half pipe at the same time.
If the man is surfing up and over a wave , then he can not be skating on a half pipe at the same time .