MathDB
2020 Team 6

Source:

February 2, 2020
team2020

Problem Statement

Misha is currently taking a Complexity Theory exam, but he seems to have forgotten a lot of the material! In the question, he is asked to fill in the following boxes with \subseteq and \subsetneq to identify the relationship between different complexity classes: NL tt P tt NP tt PH tt PSPACE tt EXP\mathsf{NL}\ \fbox{\phantom{tt}}\ \mathsf{P}\ \fbox{\phantom{tt}}\ \mathsf{NP}\ \fbox{\phantom{tt}}\ \mathsf{PH}\ \fbox{\phantom{tt}}\ \mathsf{PSPACE}\ \fbox{\phantom{tt}}\ \mathsf {EXP} and coNL tt P tt coNP tt PH\mathsf{coNL}\ \fbox{\phantom{tt}}\ \mathsf{P}\ \fbox{\phantom{tt}}\ \mathsf{coNP}\ \fbox{\phantom{tt}}\ \mathsf{PH} Luckily, he remembers that PEXP\mathsf{P} \neq \mathsf{EXP}, NLPSPACE\mathsf{NL} \neq \mathsf{PSPACE}, coNLPSPACE\mathsf{coNL} \neq \mathsf{PSPACE}, and NPcoNP    PNPPcoNP\mathsf{NP} \neq \mathsf{coNP}\implies \mathsf{P}\neq \mathsf{NP} \land \mathsf{P}\neq \mathsf{coNP}. How many ways are there for him to fill in the boxes so as not to contradict what he remembers?