What is fixed

The prescription consists of:

1. the intrinsic dilation grading (eq:grading);

2. one fixed $\varpi \in {C_c}^{\infty }({\mathbb{R}}^4;\mathbb{R})$, $\varpi (0)=1$, identical to the subtraction function chosen in XVI-J;

3. the projections built from that function, one for each order $\rho =0,1,2$;

4. zero moments on the corresponding finite Taylor complement.

The extension acts only in $z=y-w$. Smooth coefficients are restored afterwards.