Abstract
Systems of equations of the form Xi=φi(X1,...,Xn) (1≤i≤n) are considered, in which the unknowns are sets of natural numbers. Expressions φi may contain the operations of union, intersection and elementwise addition S + T = {m + n {pipe} m ε S, n ε T}. A system with an EXPTIME-complete least solution is constructed in the paper through a complete arithmetization of EXPTIME-completeness. At the same time, it is established that least solutions of all such systems are in EXPTIME. The general membership problem for these equations is proved to be EXPTIME-complete. Among the consequences of the result is EXPTIME-completeness of the compressed membership problem for conjunctive grammars.
Original language | English |
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Pages (from-to) | 319-342 |
Number of pages | 24 |
Journal | Theory of Computing Systems |
Volume | 48 |
Issue number | 2 |
DOIs | |
Publication status | Published - 1 Jan 2011 |
Scopus subject areas
- Theoretical Computer Science
- Computational Theory and Mathematics