Material equilibrium

The material equilibrium condition at constant T, P is obtained by setting, $dG=0$ \begin{equation} \sum_{\alpha}\sum_{i}\mu_{i}^{\alpha}dn_{i}^ {\alpha} \end{equation} At constant temperature and volume the equilibrium condition is given by $dA=0$ \begin{equation} dA = -SdT -PdV +\sum_{\alpha}\sum_{i}\mu_{i}^{\alpha}dn_{i}^{\alpha} \end{equation} making $dA=dT=dV=0$ obtains the same equilibrium condition as in the case of working at T,P constants.