出典:Wikipedia
出典:『Wikipedia』 (2011/04/04 00:44 UTC 版)
A read-only Turing machine or Two-way deterministic finite-state automaton (2DFA) is class of models of computability that behave like a standard Turing machine and can move in both directions across input, except cannot write to its input tape. The machine in its bare form is equivalent to a Deterministic finite-state machine or DFA in computational power, and therefore can only parse a regular language.