premise: Five adults are sitting on stone steps.
hypothesis: There are five grownups sitting on stone steps.
explanation_1: adults are same as grownups
explanation_2: Adults are grownups.
explanation_3: Adults and grownups are synonyms.  So when you say five adults are sitting on stone steps it is the same as saying five grownups are sitting on the steps.
premise_logic: exists e1 x1 x2 x3.(on(e1,x2) & n_step(x2) & of(x2,x3) & n_stone(x3) & Actor(e1,x1) & v_sit(e1) & n_adult(x1) & card_eq_5(x1))
hypothesis_logic: exists p1 x1 e1 x2 x3 x4 x5.((x1 = x2) & on(e1,x4) & n_step(x4) & of(x4,x5) & n_stone(x5) & Actor(e1,x3) & v_sit(e1) & (x2 = x3) & n_grownup(x2) & card_eq_5(x2))
premise_sim: exists e1 x1 x2 x3.(v_sit(e1) & on(e1,x2) & of(x2,x3) & n_stone(x3) & n_step(x2) & n_adult(x1) & card_eq_5(x1) & Actor(e1,x1))
hypothesis_sim: exists x1 e1 x2 x3 x4 x5.(v_sit(e1) & on(e1,x4) & of(x4,x5) & n_stone(x5) & n_step(x4) & n_grownup(x2) & card_eq_5(x2) & Actor(e1,x3) & (x2 = x3) & (x1 = x2))