premise: A firefighter is on the roof.
hypothesis: Nobody on the roof
explanation_1: If a firefighter is on the roof then someone is on the roof, not nobody.
premise_logic: exists p1 x1 x2.(n_roof(x2) & on(x1,x2) & n_firefighter(x1))
hypothesis_logic: exists x2.(n_roof(x2) & -exists x1.(a_topic(x1) & on(x1,x2) & n_person(x1)))
premise_sim: exists x1 x2.(on(x1,x2) & n_roof(x2) & n_firefighter(x1))
hypothesis_sim: exists x2.(n_roof(x2) & all x1.(-on(x1,x2) | -n_person(x1) | -a_topic(x1)))