The boy is jumping in the air.
Several young boys are playing in the garden jumping into the air
There is one boy, not several boys. He isn't necessarily in the garden.
exists e1 x1 x2.(n_air(x2) & n_boy(x1) & in(e1,x2) & Actor(e1,x1) & v_jump(e1))
exists e1 e2 s1 s2 x1 x2 x3 x4.(n_air(x4) & n_garden(x2) & in(e1,x2) & into(e2,x4) & Actor(e2,x3) & v_jump(e2) & (x2 = x3) & Actor(e1,x1) & v_play(e1) & n_boy(x1) & a_young(s2) & Theme(s2,x1) & a_several(s1) & Theme(s1,x1))