Summary: Robustness of PSPACE-complete sets
A. Pavan a,1
and Fengming Wang b,1
aDepartment of Computer Science, Iowa State University.
bDepartment of Computer Science, Rutgers University.
We study the robustness of complete languages in PSPACE and prove that they are
robust against P-selective sparse sets. Earlier similar results are known for EXP-
complete sets  and NP-complete sets .
Key words: Computational Complexity, Complete Sets, Robustness, P-selective
This paper studies the robustness of complete sets which was initiated by
Sch¨oning . Informally, a complete set is robust if it remains complete/hard
even after we remove a small amount of information from it. More formally, if
L is complete for a complexity class C, we say L is robust against a set S if
L - S is remains complete/hard for C.
Several results are known regarding the robustness of complete sets for classes