public MyPoint add_point(MyPoint p) { return(new MyPoint(x + p.x, y + p.y, z + p.z, g)); }
public MyPoint diff_point(MyPoint p) { return(new MyPoint(x - p.x, y - p.y, z - p.z, g)); }
public MyPoint add_point(MyPoint p) { return(new MyPoint(x + p.x, y + p.y, z + p.z, g)); }
public MyPoint diff_point(MyPoint p) { return(new MyPoint(x - p.x, y - p.y, z - p.z, g)); }