premise: Four boys in water are hanging on to the concrete ledge.
hypothesis: the four boys are swimming
explanation_1: Boys in water are not necessarily swimming. Boys may hang on to the concrete ledge while in water when they are not swimming.
premise_logic: exists e1 s1 x1 x2 x3.(n_ledge(x3) & a_concrete(s1) & Theme(s1,x3) & r_on(e1) & to(e1,x3) & Actor(e1,x1) & v_hang(e1) & in(x1,x2) & n_water(x2) & n_boy(x1) & card_eq_4(x1))
hypothesis_logic: exists e1 x1.(n_boy(x1) & card_eq_4(x1) & Actor(e1,x1) & v_swim(e1))
premise_sim: exists e1 s1 x1 x2 x3.(v_hang(e1) & to(e1,x3) & r_on(e1) & n_water(x2) & n_ledge(x3) & n_boy(x1) & in(x1,x2) & card_eq_4(x1) & a_concrete(s1) & Theme(s1,x3) & Actor(e1,x1))
hypothesis_sim: exists e1 x1.(v_swim(e1) & n_boy(x1) & card_eq_4(x1) & Actor(e1,x1))