A man dust mopping the floor while riding a conveyor belt.
There is a man cleaning the floors.
One way of cleaning the floors is by mopping it.
exists e1 e2 x1 x2 x3 x4 x5 x6.(n_floor(x4) & a_topic(x1) & while(e1,e2) & Theme(e2,x5) & Actor(e2,x3) & v_ride(e2) & n_belt(x5) & of(x5,x6) & n_conveyor(x6) & Theme(e1,x4) & Actor(e1,x3) & v_mop(e1) & (x1 = x3) & n_dust(x1) & of(x1,x2) & n_man(x2))
exists p1 x1 x4.(n_floor(x4) & exists e1 x2 x3.((x1 = x2) & Theme(e1,x4) & Actor(e1,x3) & v_clean(e1) & (x2 = x3) & n_man(x2)))