A old man and a youth work on starting a tiller.
Grandpa and grandson start a tiller
The old man and youth do not have to be grandpa and grandson.
exists e1 s1 s2 x1 x2 x3 x4 x5.(a_topic(s1) & subset_of(x2,s1) & Theme(e1,x5) & Actor(e1,x4) & v_start(e1) & n_tiller(x5) & (x2 = x4) & n_work(x2) & of(x2,x3) & n_youth(x3) & subset_of(x1,s1) & n_man(x1) & a_old(s2) & Theme(s2,x1))
exists e1 x1 x2 x3 x4.(ne_nam_grandson(x3) & ne_geo_grandpa(x2) & Theme(e1,x4) & Actor(e1,x1) & v_start(e1) & n_tiller(x4) & subset_of(x3,x1) & subset_of(x2,x1))