A snowboarder glides through the air.
A snowboarder is doing a trick down the snow hill.
Gliding through the air doesn't  necessarily mean going down a snow hill.
exists e1 x1 x2.(n_air(x2) & through(e1,x2) & Actor(e1,x1) & v_glide(e1) & n_snowboarder(x1))
exists e1 x1 x2 x3 x4.(n_hill(x3) & of(x3,x4) & n_snow(x4) & Theme(e1,x2) & Actor(e1,x1) & v_do(e1) & down(x2,x3) & n_trick(x2) & n_snowboarder(x1))