Discussion NotesI will post notes from each discussion section here.
Covers general information, some proofs from previous classes, and hints on homework 1.
Covers hints on homework 2, concatenation and intersection, differences between DFAs and NFAs, and example 1.13/1.15 from the book.
Covers hints on homework 3, and a couple examples of decision procedures.
Covers hints on homework 4, the pumping lemma, and example context-free grammars.
Covers hints on homework 5, the decision procedures we have seen so far, the closure properties we know so far, and an example of using the pumping lemma for CFLs.
Covers hints on homework 6, except for problems 1 and 5. Also goes through a PDA example.
Covers a multi-head Turing machine variant, and decision problems as deciders.
Takes another look at the halting problem, undecidibility, and starts to introduce reduction.
Revists the emptiness and equivalence problems for Turing machines, providing more formal reductions. Also summarizes several of the methods we've seen so far.
Last discussion section. Focuses on proving SUBSET-SUM is NP complete.