= {a,b}: 1. (9 pts) Consider the following three languages, all subsets of S* where •...
1. Construct a DFA that recognizes each of the following languages: a. L1 = {w € {a, b}* | w contains at least two a's and at least two b’s} b. L2 = {w € {a,b}* | w does not contain the substring abba} C. L3 = {w € {a, b}* | the length of w is a multiple of 4}
Construct DFA's that recognize the following languages over the alphabet {a,b}: 1. {w|w is any string except abba or aba}. Prove that your DFA recognizes exactly the specified language. 2. {w|w contains a substring either ababb or bbb}. Write the formal description for this DFA too.
Part B - Automata Construction Draw a DFA which accepts the following language over the alphabet of {0,1}: the set of all strings such that the number of 0s is divisible by 2 and the number of 1s is divisible by 5. Your DFA must handle all intput strings in {0,1}*. Here is a methodical way to do this: Figure out all the final states and label each with the shortest string it accepts, work backwards from these states to...
1. Design an NFA (Not DFA) of the following languages. a) Lw E a, b) lw contain substring abbaab) b) L- [w E 10,1,2) lsum of digits in w are divisible by three) c) L-(w E {0,1,2)' |The number is divisible by three} d) The language of all strings in which every a (if there are any) is followed immediately by bb. e) The language of all strings containing both aba and bab as substrings. f L w E 0,1every...
1. Construct a NESA with at least one s-moves to accept each of the following languages. (a) (we 10,1)* | w corresponds to the binary encoding of a positive integer that is (b)(a"ba" | m, n 20 and n%3 m%3} For instance, b, aba, aabaa, aaab, abaaaa, (c) (we (a,b* | w contains two consecutive b's that are not immediately followed by an divisible by 16 or is odd. aaaaabaa are in the language, but abãa is not. a'). For...
4) (9 pts) Give regular expressions for the following languages on (la, b) a) L1 = { w : na(w) mod 3 = 1). b) L2w w ends in aa) c) L3 = all strings containing no more than three a's.
(9 pts 3 pts each) For each of the following languages, name the least powerful type of machine that will accept it, and prove your answer. (Hint: a finite state automata is less powerful than a pushdown automata, which in turn is less powerful than a Turing Machine.) For example, to prove a language needs a PDA to accept it, you would use the Pumping Lemma to show it is not regular, and then build the PDA or CFG that...
Pumping lemma s. (7+5 points) Pumping lemma for regular languages. In all cases, -a,b) a) Consider the following regular language A. ping length p 2 1. For each string s e pumping lemma, we can write s -xy, with lyl S p, and s can be pumped. Since A is regular, A satisfies the pumping lemma with pum A, where Is] 2 p, by the a) Is p 3 a pumping length for language 4? (Yes/No) b) Show that w...
UueSLIORS! 1. Find the error in logic in the following statement: We know that a b' is a context-free, not regular language. The class of context-free languages are not closed under complement, so its complement is not context free. But we know that its complement is context-free. 2. We have proved that the regular languages are closed under string reversal. Prove here that the context-free languages are closed under string reversal. 3. Part 1: Find an NFA with 3 states...