1. Finite Automata Finite-state machine with no output. FA consists of States, Transitions between states FA is a 5-tuple Example! A string x is recognized or accepted by the FA if it takes the initial state q 0 to the final state. The language of FA M is L(M) Whats the language recognized by the above FA? Two finite-state automata are equivalent if they recognize the same language. Is 100110 accepted?

2. Finite Automata Deterministic FA’s: –For each pair of state and input value there is a unique next state given by the transition function Non-deterministic FA’s (NFA): –several possible next states for the next state and hence several possible computations. Non-determinism viewed as parallel computation

3. Finite Automata –NFA is a 5-tuple function Where is the transition function –String x is accepted of recognized if there is a final state in the set of all states that can be obtained from s 0 using x. Every NFA is also recognized by a FA FA’s to compute relatively simple functions Limited memory. Recognize only regular sets.