1. Lecture # 7 Theory Of Automata By Dr. MM Alam
  2. Lecture#6 Recap • JFLAP Introduction • Practical Demonstration of JFLAP
  3. DFA definition Recap • An FA is defined as follows:- – Finite no of states in which one state must be initial state and more than one or may be none can be the final states. – Sigma Σ provides the input letters from which input strings can be formed. – FA Distinguishing Rule: For each state, there must be an out going transition for each input letter in Sigma Σ.
  4. Construct a regular expression and correspondingly an FA for all strings that end in a double letter. • The regular expression is as follows:- • (a+b)*(aa+bb) a a 1- 1 2+ b a a b b b a 4+ b 3+
  5. • Beginning and ending in different letters – a(a+b)*b + b(a+b)*a
  6. FA Optionality Behavior • Can and Cannot represent Even-Even Language
  7. Dead or Trap States • Dead states are used to implement the FA Distinguishing Rule. • How to use JFLAP to draw dead states
  8. JFLAP Tour (Again) • Even-Even Language in JFLAP • Multiple Input Examples running using JFLAP
  9. Lecture#7 Summary • FA definition RECAP • How to build an FA from scratch • What are Dead or Trap states in FA • Trap or dead state Example using JFLAP