}$ defines an isomorphism of $\tilde{\bbZ}[\bfq]$-algebras $$\xymatrix{ \cH_0(\bfq)\otimes_{\bbZ}\tilde{\bbZ}\ar[r]^<<<<<{\sim} & \cH_{\tilde{\bbZ}}^{\gamma}(\bfq), }$$ such that $S\otimes 0\mapsto S\varepsilon_{\gamma}$, $U\otimes 0\mapsto U\varepsilon_{\gamma}$ and $S_0\otimes 0\mapsto S_0\varepsilon_{\gamma}$.  \[presA0q\] We 