A man is giving a presentation using a projector.
A man is shoveling snow.
One can not be shoveling snow and giving a presentation simultaneously.
exists e1 e2 x1 x2 x3.(for(e1,e2) & Theme(e2,x3) & Actor(e2,x1) & v_use(e2) & n_projector(x3) & Theme(e1,x2) & Actor(e1,x1) & v_give(e1) & n_presentation(x2) & n_man(x1))
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_shovel(e1) & n_snow(x2) & n_man(x1))