A group of people are sitting at a table eating.
A group of people are scuba diving.
If people are scuba diving they cannot be sitting at a table eating.
exists e1 x1 x2 x3 x4.(at(e1,x3) & n_eating(x3) & of(x3,x4) & n_table(x4) & Actor(e1,x1) & v_sit(e1) & of(x1,x2) & n_people(x2) & n_group(x1))
exists s1 x1 x2 x3.(Time(s1,x3) & n_diving(x3) & Theme(s1,x1) & a_scuba(s1) & of(x1,x2) & n_people(x2) & n_group(x1))