Empty Alternation

We introduce the notion of empty alternation by investigating alternating automata which are restricted to empty their storage except for a logarithmically space-bounded tape before making an alternating transition. In particular, we consider the cases when the depth of alternation is bounded by a constant or a polylogarithmic function. In this way we get new characterizations of the classes ACk , SACk and P using a push-down store and new characterizations of the class P 2 using Turing tapes.

• Type: Conference
• Year: 1994
• Where: MFCS
• Authors: Klaus-Jörn Lange, Klaus Reinhardt
• Keywords: Empty Alternation, MFCS 1994, Polylogarithmic Function, Space-bounded Tape, Theoretical Computer Science