Context-dependent nondeterminism for pushdown automata

Regulated Nondeterminism in Pushdown Automata

Measuring Nondeterminism in Pushdown Automata

The amount of nondeterminism that a pushdown automaton requires to recognize an input string can be measured by the minimum number of guesses that it must make to accept the string, where guesses are measured in bits of information. When this quantity is unbounded, the rate at which it grows as the length of the string increases serves as a measure of the pushdown automaton’s “rate of consumpti...

Removing Nondeterminism in Constant Height Pushdown Automata

We study the descriptional cost of removing nondeterminism in constant height pushdown automata — i.e., pushdown automata with a built-in constant limit on the height of the pushdown. We show a double-exponential size increase when converting a constant height nondeterministic pushdown automaton into an equivalent deterministic device. Moreover, we prove that such a double-exponential blow-up c...

Regulated Nondeterminism in Pushdown Automata: The Non-Regular Case

We continue the investigation of pushdown automata which are allowed to make a nondeterministic decision if and only if their pushdown content forms a string belonging to a given control language. We prove that if the control language is linear and non-regular, then the power of pushdown automata regulated in this way is increased to the power of Turing machines. From a practical point of view,...

Automata for Context-Dependent Connectors

Recent approaches to component-based software engineering employ coordinating connectors to compose components into software systems. For maximum flexibility and reuse, such connectors can themselves be composed, resulting in an expressive calculus of connectors whose semantics encompasses complex combinations of synchronisation, mutual exclusion, non-deterministic choice and state-dependent be...