1. Write regular expressions to capture the following regular languages:
(a) The set of binary strings which have a 1 in every even position. (Note: odd positions may be either 0 or 1.)
(b) The set of binary strings that do not contain 011 as a substring.
(c) Comments in Pascal. These are delimited by (* and *) or by { and }, and can contain anything in between; they are NOT allowed to nest, however.
2. Write a DFA or NFA to recognize the languages described in each part of problem 1.
3. (a) Show the NFA that results from applying the standard construction to the regular expression letter(letter|digit)∗.
(b) Convert your NFA to a DFA




1. Write regular expressions to capture the following regular languages: (a) The set of binary strings...
Regular expressions, DFA, NFA, grammars, languages
Regular Languages 4 4 1. Write English descriptions for the languages generated by the following regular expressions: (a) (01... 9|A|B|C|D|E|F)+(2X) (b) (ab)*(a|ble) 2. Write regular expressions for each of the following. (a) All strings of lowercase letters that begin and end in a. (b) All strings of digits that contain no leading zeros. (c) All strings of digits that represent even numbers. (d) Strings over the alphabet {a,b,c} with an even number of a's....
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.
Exercise 3.1.1: Write regular expressions for the following languages: * a) The set of strings over alphabet {a,b,c} containing at least one a and at least one b. b) The set of strings of O's and l’s whose tenth symbol from the right end is
Give regular expressions for the following languages: (a) The language of all strings over {a,b} except the empty string. (b) The language of all strings over {a,b} that contain both bab and bba as substrings. (c)L k = {w ∈ {a,b} * | w contains a substring having 3 more b’s than a’s}. (d) The language of all strings over {a,b} that have a b in every odd position (first symbol is considered position 1; empty string should be accepted)...
1. Write DFA, NFA (small), regular expression and right linear grammar for strings over {a,b} a. End in either aa or bb b. ( an | bna) n >= 0 c. {w : w such that w contains the substring “bb” or w contains an odd number of a’s (or both). d. {w : w does not contain exactly two a’s} e. { w : w starts with substring abb and contains substring bba}
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
Construct NFAs for the following languages: 1. The set if binary strings such that the number of 0's is a multiple of 3 or the number of 1's is a multiple of 5. 2. The set of all binary strings containing 101 or 100 as substring 3. The set of all strings such that the 12th symbol from the right end is 0
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!!!
Construct regular expressions for the following languages over the alphabet {a, b}: a. Strings that do not begin with an “a”. b. Strings that contain both aa and bb as substrings.
Give English descriptions of the languages represented by the following regular expressions. The descriptions should be simple, similar to how we have been defining languages in class(e.g., “languages of binary strings containing 0 in even positions. . .”). Note: While describing your language, you don’t want to simply spell out the conditions in your regular expressions. E.g., if the regular expression is 0(0 + 1)∗, an answer of the sort “language of all binary strings that start with a 0”...