premise: Tractor doing construction work.
hypothesis: A blue tractor is doing construction work.
explanation_1: You can not infer it's a blue tractor.
explanation_2: The color blue is not stated.
explanation_3: All tractors are not blue.
premise_logic: exists e1 x1 x2 x3.(ne_nam_tractor(x1) & Theme(e1,x2) & Actor(e1,x1) & v_do(e1) & n_work(x2) & of(x2,x3) & n_construction(x3))
hypothesis_logic: exists e1 s1 x1 x2 x3.(Theme(e1,x2) & Actor(e1,x1) & v_do(e1) & n_work(x2) & of(x2,x3) & n_construction(x3) & n_tractor(x1) & a_blue(s1) & Theme(s1,x1))