  However, while it seems clear that \(\P\) is strictly contained in \(\NP\), that \(\NP\) is strictly contained in \(\PSPACE\), and that \(\PSPACE\) is strictly contained in \(\EXPTIME\), none of these inequalities has been proved. In fact, it is not even known that \(\P\) is different from \(\PSPACE\), nor that \(\NP\) is different from \(\EXPTIME\). The only known proper inclusion from the above is that \(\P\) is strictly contained in \(\EXPTIME\). The remaining questions concerning the relative power of different computational resources are fundamental unsolved problems in the theory of computation.