A guy wearing protective gear is welding a steel beam.
The man is not wearing protective gear while welding.
A person is either wearing protective gear, or they are not.
exists e2 e1 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 x1.(n_man(x1) & -exists e2 e1 s1 x2.(while(e1,e2) & Actor(e2,x1) & v_weld(e2) & Theme(e1,x2) & Actor(e1,x1) & v_wear(e1) & n_gear(x2) & a_protective(s1) & Theme(s1,x2)))