The karate class is performing outside.
The karate class fights a group of assailants.
Performing can not be done while fighting a group of assailants.
exists e1 s1 s2 x1.(n_class(x1) & a_karate(s1) & Theme(s1,x1) & a_outside(s2) & Manner(e1,s2) & Actor(e1,x1) & v_perform(e1))
exists e1 s1 x1 x2 x3.(n_class(x1) & a_karate(s1) & Theme(s1,x1) & Theme(e1,x2) & Actor(e1,x1) & v_fight(e1) & of(x2,x3) & n_assailant(x3) & n_group(x2))