A guy wearing protective gear is welding a steel beam.
The man is reparing a part of a building.
A guy welding a steel beam doesn't have to be reparing a part of a building.
exists e1 e2 s1 x1 x2 x3 x4 x5.(Theme(e2,x4) & Actor(e2,x1) & v_weld(e2) & n_beam(x4) & of(x4,x5) & n_steel(x5) & Theme(e1,x3) & Actor(e1,x2) & v_wear(e1) & n_gear(x3) & a_protective(s1) & Theme(s1,x3) & (x1 = x2) & n_guy(x1))
exists e1 x1 x2 x3.(n_man(x1) & Theme(e1,x2) & Actor(e1,x1) & v_repare(e1) & of(x2,x3) & n_building(x3) & n_part(x2))