a lone scientist digging in the rock for artifacts.
A student digging for gold.
Artifacts are not the same as gold.
exists e1 s1 x1 x2 x3 x4.(n_rock(x3) & a_topic(x1) & in(e1,x3) & for(x3,x4) & n_artifact(x4) & Actor(e1,x2) & v_dig(e1) & (x1 = x2) & n_scientist(x1) & a_lone(s1) & Theme(s1,x1))
exists e1 x1 x2 x3.(a_topic(x1) & for(e1,x3) & n_gold(x3) & Actor(e1,x2) & v_dig(e1) & (x1 = x2) & n_student(x1))