premise: Several firemen stand or sit on a gray roof while working.
hypothesis: Several fireman are working on a gray roof.
explanation_1: If several firemen stand or sit on a gray roof while working then they are working on a gray roof.
explanation_2: Working on the roof, the men would have to be on it.
explanation_3: The men are working on a roof.
premise_logic: (exists e1 s1 x1.(Actor(e1,x1) & v_stand(e1) & n_fireman(x1) & a_several(s1) & Theme(s1,x1)) | exists e2 e3 s2 s3 x2 x3.(while(e2,e3) & Actor(e3,x2) & v_work(e3) & on(e2,x3) & n_roof(x3) & a_gray(s3) & Theme(s3,x3) & Actor(e2,x2) & v_sit(e2) & n_fireman(x2) & a_several(s2) & Theme(s2,x2)))
hypothesis_logic: exists e1 s1 s2 x1 x2.(on(e1,x2) & n_roof(x2) & a_gray(s2) & Theme(s2,x2) & Actor(e1,x1) & v_work(e1) & n_fireman(x1) & a_several(s1) & Theme(s1,x1))