Three-way two-dimensional finite automata with rotated inputs

This paper introduces a new type of two-dimensional automaton called a three-way two-dimensional finite automaton with rotated inputs, and investigates a relationship among the accepting powers of these new automata, two-dimensional finite automata, and tape-bounded three-way two-dimensional Turing machines. We show, for example, that m log m space (m2 space) is necessary and sufficient for deterministic three-way two-dimensional Turing machines to simulate deterministic (nondeterministic) three-way two-dimensional finite automata with rotated inputs.