28/02/2019: problems 2 (parenthesis expressions) and 3 (semilinear sets).
07/03/2019: problems 3 (semilinear sets), 10 (regular expression for sum in binary), 9, 11 (DFA for divisibility), 12 (NFA over one letter alphabet), and 13 (NFA for semilinear sets in binary).
21/03/2019: closure properties of regular languages: root (p. 30); minimal automata (p. 44); using Myhill-Nerode to prove non-regularity (palindromes, p. 16) and exponential lower bounds on minimal DFA (p. 63.1); parsing with NFA (p. 69).
28/03/2019: long rejected words (p. 64); converting expressions to linear NFA; parsing with regular expressions (p. 70.2, 71).