A person is cropping grass by driving a mechanical grass cutter vehicle
The person is eating at a restaurant.
Grass generally grows outdoors. Eating at a restaurant generally happens indoors. So if he or she is cropping grass, he or she is likely not eating at a restaurant.
exists e2 e1 s1 x1 x2 x3 x4 x5.(by(e1,e2) & Theme(e2,x3) & Actor(e2,x1) & v_drive(e2) & n_vehicle(x3) & of(x3,x5) & n_cutter(x5) & of(x3,x4) & n_grass(x4) & a_mechanical(s1) & Theme(s1,x3) & Theme(e1,x2) & Actor(e1,x1) & v_crop(e1) & n_grass(x2) & n_person(x1))
exists e1 x1 x2.(n_person(x1) & at(e1,x2) & n_restaurant(x2) & Actor(e1,x1) & v_eat(e1))