Person in a racing ski outfit and a helmet is skiing while in a squat position.
A boy in a swimming outfit prepares to swim.
You cannot be swimming and skiing at the same time.
exists e1 s1 x1 x2 x3 x4 x5 x6 x7.(ne_tim_person(x1) & in(e1,x7) & n_position(x7) & a_squat(s1) & Theme(s1,x7) & r_while(e1) & Actor(e1,x1) & v_ski(e1) & in(x1,x2) & subset_of(x6,x2) & n_helmet(x6) & subset_of(x3,x2) & n_outfit(x3) & of(x3,x5) & n_ski(x5) & of(x3,x4) & n_racing(x4))
exists e1 p1 x1 x2 x3.(Topic(e1,p1) & Actor(e1,x1) & v_prepare(e1) & exists e2.(Actor(e2,x1) & v_swim(e2)) & in(x1,x2) & n_outfit(x2) & of(x2,x3) & n_swimming(x3) & n_boy(x1))