Two guys in a boat sailing along the ocean.
A single boat sails across the ocean with two men
"A single boat" is a rephrasing of "a boat."
exists x1 x2 x3 x4.(n_ocean(x4) & a_topic(x1) & along(x1,x4) & in(x1,x2) & n_sailing(x2) & of(x2,x3) & n_boat(x3) & n_guy(x1) & card_eq_2(x1))
exists s1 x1 x2 x3 x4.(n_ocean(x3) & a_topic(x1) & with(x1,x4) & n_man(x4) & card_eq_2(x4) & across(x1,x3) & n_sail(x1) & of(x1,x2) & n_boat(x2) & a_single(s1) & Theme(s1,x1))