a man climbs a large rock.
A man is climbing.
"is climbing" is a rephrasing of "climbs"
exists e1 s1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_climb(e1) & n_rock(x2) & a_large(s1) & Theme(s1,x2) & n_man(x1))
exists e1 x1.(Actor(e1,x1) & v_climb(e1) & n_man(x1))