Write a grammar for the language consisting of strings built only of the letters a and b. the strings may have any number of these letters, but the letter combinations bb must be in each string somewhere, and each string must end with a ba.

Show that there is a language a ⚆ {0, 1} â— with the following properties: 1. for all x â a, |x| ≤ 5. 2. no dfa with fewer than 9 states recognizes a. hint: you don’t have to define a explicitly; just show that it has to exist. count the number of languages satisfying (1) and the number of dfas satisfying (2), and argue that there aren’t enough dfas to recognize all those languages. to count the number of languages satisfying (1), think about writing down all the strings of length at most 5, and then to define such a language, you have to make a binary decision for each string about whether to include it in the language or not. how many ways are there to make these choices? to count the number of dfas satisfying (2), consider that a dfa behaves identically even if you rename all the states, so you can assume without loss of generality that any dfa with k states has the state set {q1, q2, . . , qk}. now think about how to count how many ways there are to choose the other four parts of the dfa.

Which syntax error in programming is unlikely to be highlighted by a compiler or an interpreter? a variable name misspelling a missing space a comma in place of a period a missing closing quotation mark

Fall protection, confined space entry procedures, controlled noise levels, and protection from chemical hazards are some of the things that contribute to a safe what