A man doing an experiment.
A man is experimenting.
doing an experiment is rephrase of experimenting
exists e1 x1 x2 x3.(a_topic(x1) & Theme(e1,x3) & Actor(e1,x2) & v_do(e1) & n_experiment(x3) & (x1 = x2) & n_man(x1))
exists e1 x1.(Actor(e1,x1) & v_experiment(e1) & n_man(x1))