A man in a blue shirt is tossing a football.
A man is practicing for football tryouts.
Tossing a football does not necessarily mean practicing for football tryouts.
exists e1 s1 x1 x2 x3.(Theme(e1,x3) & Actor(e1,x1) & v_toss(e1) & n_football(x3) & in(x1,x2) & n_shirt(x2) & a_blue(s1) & Theme(s1,x2) & n_man(x1))
exists e1 x1 x2 x3.(for(e1,x2) & n_tryout(x2) & of(x2,x3) & n_football(x3) & Actor(e1,x1) & v_practice(e1) & n_man(x1))