In other words, I will write if between o x b sorry, x b y b z b and x y z is too small, actually you know epsilon into epsilon it is order of what you know mathematically it is what is called, it is a second order quantity you know, if there is a small thing that, if I have the small into another small makes it small square see point 01 into point 01 makes it very small you know like that.
We need not worry about that, but if you want if somebody wants very rigorously mathematical the consistent then it one can explain. Now, we will define for us the motions sorry x y z; that means, it is above then axis which is fixed on the ship, but not rotating just transferring; that means, it is see the ship is like that, but the axis remains like this, ship is like that but the axis remains like this, the axis is going with the ship, but not fixed on the ship, axis origin only its fixed on the ship, only the G point is fixed on the ship .