Circuits and Expressions over Finite Semirings

Autor: Danny Hucke, Markus Lohrey, Daniel König, Moses Ganardi
Rok vydání: 2018
Předmět:
Zdroj: ACM Transactions on Computation Theory. 10:1-30
ISSN: 1942-3462
1942-3454
DOI: 10.1145/3241375
Popis: The computational complexity of the circuit and expression evaluation problem for finite semirings is considered, where semirings are not assumed to have an additive or a multiplicative identity. The following dichotomy is shown: If a finite semiring is such that (i) the multiplicative semigroup is solvable and (ii) it does not contain a subsemiring with an additive identity 0 and a multiplicative identity 1 ≠ 0, then the circuit evaluation problem is in DET ⊆ NC 2 , and the expression evaluation problem for the semiring is in TC 0 . For all other finite semirings, the circuit evaluation problem is P-complete and the expression evaluation problem is NC 1 -complete. As an application, we determine the complexity of intersection non-emptiness problems for given context-free grammars (regular expressions) with a fixed regular language.
Databáze: OpenAIRE