From bidirectionality to alternation

From Bidirectionality to Alternation

We describe an explicit simulation of 2-way nondeterministic automata by 1-way alternating automata with quadratic blow-up. We first describe the construction for automata on finite words, and extend it to automata on infinite words.

From Bidire tionality to Alternation

Achieving bidirectionality

The topic of BIDIltECT1ONAL1TY~ using common knowledge in language processing for both anMysis and generation, is of both practical and theoretical concern. Theoretically, it is important to determine what knowledge structures can be applied to both. Practically, it is important that a cmnpetent natural language system be ~ble to generate outputs tilat are relevant to the inputs it understands,...

Removing Bidirectionality from Nondeterministic Finite Automata

We prove that every two-way nondeterministic finite automaton with n states has an equivalent one-way nondeterministic finite automaton with at most 2n n+1 states. We also show this bound is exact.

Bidirectionality in synesthesia: evidence from a multiplication verification task.

Color-grapheme synesthetes automatically perceive achromatic numbers as colored (e.g., 7 is turquoise). Up until recently, synesthesia was believed to be unidirectional. For instance, the number 7 gives rise to the percept of turquoise but the perception of turquoise does not trigger the number 7. However, some recent studies argue for bidirectional connections Cohen Kadosh et al., 2005; Johnso...