Three children are on the floor playing with building blocks.
A group of kids play with toys.
Three children are a group of kids, and building blocks are toys.
exists p1 x1 x2 x3.(n_playing(x2) & of(x2,x3) & n_floor(x3) & exists x4 x5.(on(x1,x2) & with(x2,x4) & n_block(x4) & of(x4,x5) & n_building(x5)) & n_child(x1) & card_eq_3(x1))
exists e1 x1 x2 x3.(with(e1,x3) & n_toy(x3) & Actor(e1,x1) & v_play(e1) & of(x1,x2) & n_kid(x2) & n_group(x1))