A worker in a vest is inspecting tiles on a roof.
The worker checks on the roof.
The word "checks on " from sentence two is a rephrasing of "inspecting" from sentence one.
exists e1 x1 x2 x3 x4.(on(e1,x4) & n_roof(x4) & Theme(e1,x3) & Actor(e1,x1) & v_inspect(e1) & n_tile(x3) & in(x1,x2) & n_vest(x2) & n_worker(x1))
exists x1 x2 x3.(n_roof(x3) & n_check(x1) & of(x1,x2) & n_worker(x2) & a_topic(x1) & on(x1,x3))