Theory of Computation

Mod-01 Lec-01 What is theory of computation?.
Mod-01 Lec-02 Introduction to finite automaton..
Mod-01 Lec-03 Finite automata continued, deterministic finite automata(DFAs),.
Mod-01 Lec-04 Regular languages, their closure properties..
Mod-01 Lec-05 DFAs solve set membership problems in linear time, pumping lemma..
Mod-01 Lec-06 More examples of nonregular languages, proof of pumping lemma.
Mod-01 Lec-07 A generalization of pumping lemma, nondeterministic finite automata (NFAs).
Mod-01 Lec-08 Formal description of NFA, language accepted by NFA, such languages are also regular..
Mod-01 Lec-09 'Guess and verify' paradigm for nondeterminism..
Mod- 01 Lec-10 NFA's with epsilon transitions..
Mod-01 Lec-11 Regular expressions, they denote regular languages..
Mod-01 Lec-12 Construction of a regular expression for a language given a DFA accepting it..
Mod-01 Lec-13 Closure properties continued..
Mod-01 Lec-14 Closure under reversal, use of closure properties..
Mod-01 Lec-15 Decision problems for regular languages..
Mod-01 Lec-16 About minimization of states of DFAs. Myhill-Nerode theorem..
Mod-01 Lec-17 Continuation of proof of Myhill-Nerode theorem..
Mod-01 Lec-18 Application of Myhill-Nerode theorem. DFA minimization..
Mod-01 Lec-19 DFA minimization continued..
Mod-01 Lec-20 Introduction to context free languages (cfls).
Mod-01 Lec-21 Languages generated by a cfg, leftmost derivation, more examples of cfgs and cfls..
Mod-01 Lec-22 Parse trees, inductive proof that L is L(G). All regular languages are context free..
Mod-01 Lec-23 Towards Chomsky normal forms: elimination of useless symbols.
Mod-01 Lec-24 Simplification of cfgs continued, Removal of epsilon productions.
Mod-01 Lec-25 Elimination of unit productions. Converting a cfg into Chomsky normal form..
Mod-01 Lec-26 Pumping lemma for cfls. Adversarial paradigm..
Mod-01 Lec-27 Completion of pumping lemma proof.
Mod-01 Lec-28 Closure properties continued. cfls not closed under complementation..
Mod-01 Lec-29 Another example of a cfl whose complement is not a cfl. Decision problems for cfls..
Mod-01 Lec-30 More decision problems. CYK algorithm for membership decision..
Mod-01 Lec-31 Introduction to pushdown automata (pda)..
Mod-01 Lec-32 pda configurations, acceptance notions for pdas. Transition diagrams for pdas.
Mod-01 Lec-33 Equivalence of acceptance by empty stack and acceptance by final state..
Mod-01 Lec-34 Turing machines (TM): motivation, informal definition, example, transition diagram..
Mod-01 Lec-35 Execution trace, another example (unary to binary conversion)..
Mod-01 Lec-36 Example continued. Finiteness of TM description.
Mod-01 Lec-37 Notion of non-acceptance or rejection of a string by a TM. Multitrack TM.
Mod-01 Lec-38 Simulation of multitape TMs by basic model. Nondeterministic TM (NDTM)..
Mod-01 Lec-39 Counter machines and their equivalence to basic TM model..
Mod-01 Lec-40 TMs can simulate computers, diagonalization proof..
Mod-01 Lec-41 Existence of non-r.e. languages, recursive languages, notion of decidability..Mod-01 Lec-42 Separation of recursive and r.e. classes, halting problem and its undecidability..