Czerwinski's paper "Separation of ${ \rm PSPACE}$ and ${ \rm EXP}$" [Cze21] claims to prove that ${ \rm PSPACE} \neq { \rm EXP}$ by showing there is no length-increasing polynomial-time reduction from a given ${ \rm EXP}$-complete set to a given ${ \rm PSPACE}$-complete set. However, in this critique, we show that there are fundamental flaws within the paper's approach and provide a counterexample to one of the paper's theorems, which makes the proposed proof that ${ \rm PSPACE} \neq { \rm EXP}$ insufficient.
Categories: cs.CC