Show that the set of even length strings over {a,b} in which two middle symbols are same is not regular.
Show that the set of even length strings over {a,b} in which two middle symbols are...
Write down the regular expressions for the following set of strings over {a, b}: 1.Strings that contain no more than one occurrence of the string aa. 2.All strings containing aba: 3.All strings of odd length 4.A string in this language must have at least two a's. 5.All strings that begin with a, and have an even number of b Bonus - All strings with “a” at every odd position
Submit a DFA whose language is the set of strings over {a, b} of odd length in which every symbol is the same.
1. L is the set of strings over {a, b) that begin with a and do not contain the substring bb. a. Show L is regular by giving a regular expression that denotes the language. b. Show L is regular by giving a DETERMINISTIC finite automaton that recognizes the language.
Question 1 - Regular Expressions Find regular expressions that define the following languages: 1. All even-length strings over the alphabet {a,b}. 2. All strings over the alphabet {a,b} with odd numbers of a's. 3. All strings over the alphabet {a,b} with even numbers of b’s. 4. All strings over the alphabet {a,b} that start and end with different symbols. 5. All strings over the alphabet {a, b} that do not contain the substring aab and end with bb.
1. Give a regular expression for the set of strings over {a, b, c} such that the sum of the number of a’s and the number of b’s is equal to 3.
Let Hn denote the set of strings over the alphabet {A, B, C} with no two consecutive letters the same. Let hn = |Hn|. Determine H1, H2, H3, and then find a recurrence for hn. Solve the recurrence relation you found.
Provide regular expressions for the following languages: a.) The set of strings over {0,1} whose tenth symbol from the right end is 1. b) The set of strings over {0,1} not containing 101 as a sub-string. ***IMPORTANT: PLEASE SHOW ALL WORK AND ALL STEPS, NOT JUST THE ANSWERS!!!
****** Theory of Computing ********* 1. Provide a regular expression for “all even length strings of b’s”. 2. List all words of length 4 in Language((a+b)* a). Also, provide an English description of this language.
Provide a regular expression for the following languages: (a) the set of all strings over {a, b} that start with ab and end with ba, (b) the set of strings over {a, b} where four consecutive occurrences of both letters occur in every word.
Let n be an even number. How many ternary strings (i.e. strings over the alphabet 10, 1,2]) of length n are there in which the only places that zeroes can appear are in the odd-numbered positions?