A young man and mother in the kitchen washing and drying the dishes.
a couple is cleaning the back ward
No one would describe a young man and his mother as a couple, they are two different relationships.
exists e1 s1 s2 x1 x2 x3 x4 x5 x6 x7.(n_dish(x7) & n_washing(x3) & of(x3,x4) & n_kitchen(x4) & a_topic(s1) & subset_of(x5,s1) & Theme(e1,x7) & Actor(e1,x6) & v_dry(e1) & (x5 = x6) & n_mother(x5) & subset_of(x2,s1) & in(x2,x3) & n_mother(x2) & subset_of(x1,s1) & n_man(x1) & a_young(s2) & Theme(s2,x1))
exists e1 x1 x2 x3.(n_ward(x2) & of(x2,x3) & n_back(x3) & Theme(e1,x2) & Actor(e1,x1) & v_clean(e1) & n_couple(x1))