M an Amodule, $S\subset A$ a multiplicative subset. Is it possible for $S^{1}M$ to have an $S^{1}A$module structure satisfying $\frac{a}{1}\cdot\frac{m}{1}=\frac{am}{1}$ other than the "usuall" one given by $\frac{a}{s}\cdot\frac{m}{t}=\frac{am}{st}$ ?
