18.404J/6.840J The Theory of Computation(Fall 2020, MIT OCW). Instructor: Prof. Michael Sipser. This course emphasizes computability and computational complexity theory. Topics include regular and context-free languages, decidable and undecidable problems, reducibility, recursive function theory, time and space measures on computation, completeness, hierarchy theorems, inherently complex problems, oracles, probabilistic computation, and interactive proof systems.
(from ocw.mit.edu)
Quickly reviewed last lecture. Introduced nondeterministic finite automata (NFA). Proved that NFA and DFA are equivalent in power. Proved that the class of regular languages is closed under concatenation and star. Showed conversion of regular expressions to NFAs.