A man wearing a gray shirt is doing a skateboard trick on stairs.
The man can ride a skateboard
Doing a skateboard trick implies that the man can ride a skateboard
exists e1 e2 s1 x1 x2 x3 x4 x5 x6.(Theme(e2,x4) & Actor(e2,x1) & v_do(e2) & on(x4,x6) & n_stair(x6) & n_trick(x4) & of(x4,x5) & n_skateboard(x5) & Theme(e1,x3) & Actor(e1,x2) & v_wear(e1) & n_shirt(x3) & a_gray(s1) & Theme(s1,x3) & (x1 = x2) & n_man(x1))
exists e1 p1 x1.(n_man(x1) & exists e2 x2.(Theme(e2,x2) & Actor(e2,x1) & v_ride(e2) & n_skateboard(x2)) & Topic(e1,p1) & Actor(e1,x1) & v_can(e1))