A man on a four-wheeler jumps while in a field.
A man dives off his four-wheeler while in a jump.
The fact that a man on a four-wheeler jumps doesn't imply that he dives off while in jump.
(x)
exists e1 s1 x1 x2 x3.(in(e1,x3) & n_jump(x3) & r_while(e1) & a_off(s1) & Manner(e1,s1) & Theme(e1,x2) & Actor(e1,x1) & v_dive(e1) & n_four-wheeler(x2) & of(x2,x1) & n_male(x1) & n_man(x1))