Degree-languages: A new concept of acceptance

Detlef Wotschke
1977 Journal of computer and system sciences (Print)  
The concept of acceptance degree is introduced. A string is accepted by a recognition device if and only if its acceptance degree is not less than a preselected rational number. A degree-language is the set of all those strings. The class of degree-languages over pushdown automata (linear bounded automata) contains the intersection-closure and the complements of the context-free (context-sensitive) languages and it is contained in the Boolean closure of the context-free (context-sensitive)
more » ... ages. Consequently degreelanguages over pushdown automata can be recognized as fast as context-free languages. The class of context-sensitive languages is closed under complementation if and only if eveG, degree-language over a linear bounded automaton is either context-sensitive or is the complement of a context-sensitive language.
doi:10.1016/s0022-0000(77)80012-3 fatcat:bwvxnqcrxrhvbb3skz5bmge4mu