the young children are petting a piglet
Young humans are with a young pig.
A YOUNG PIG IS A PIGLET.
exists e1 s1 x1 x2.(n_child(x1) & a_young(s1) & Theme(s1,x1) & Theme(e1,x2) & Actor(e1,x1) & v_pet(e1) & n_piglet(x2))
exists p1 s1 x1.(exists s2 x2.(with(x1,x2) & n_pig(x2) & a_young(s2) & Theme(s2,x2)) & n_human(x1) & a_young(s1) & Theme(s1,x1))