  Two simple homotopy equivalent 2-complexes K2 and L2 are related by an
algebraic criterion of their corresponding presentations as stated in
[HoMeSier]. Frank Quinn set it into a topological context (see [Qu1]) and call
these 2-complexes related by an s-move. Using elementary 3-expansions, K2
extends to 3-cells in K3 respectively L2 to 3-cells in L3. By associating both
explorations we obtain a decomposition of the s-move 3-cells into a sequence of
2-cells. We present ideas, sketch of proofs and problems to use it for
constructing an Andrews-Curtis invariant on s-move 3-cells.
