class Square{
    int hg;
    int vg;
    int state;
    Square ul;
    Square u;
    Square ur;
    ....


    public Square(...){
        //a constructor, as necessary
    }

    public Square(... ...){
        //another constructor, as necessary
    }

    public Square cons_down(Square initial){
        Square n = new Square(initial.hg, inital.vg+1, etc...);
        return n;
    }

}