A man in a blue uniform holding a mop , and looking down at the floor .
the man is sweeping the stairs
A man in a blue uniform holding a mop, and looking down at the floor.
the man is sweeping the stairs
The man is either sweeping or mopping but not both; also, he is either on a flat floor or on the stairs, but not both.
The man is either sweeping or mopping but not both ; also , he is either on a flat floor or on the stairs , but not both .