Library/Finite automata/2DFA 2DFA · Regular last-letter scan @thethinkmachine·version 1·CC BY 4.0·added 28 Sept 2026 The textbook Two-Way Deterministic Finite Automaton example. Open in AutomataStudio More ▾ Open in the desktop app Download the .automaton file Source on GitHub startscanlast_alast_baccept⊢ababab⊣ The machine as drawn — 5 states, 8 transitions.