
Database System Concepts
7th Edition
ISBN: 9780078022159
Author: Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan
Publisher: McGraw-Hill Education
expand_more
expand_more
format_list_bulleted
Question

Transcribed Image Text:A = {a, ab, aab},
A set of strings over the alphabet (a, b). For strings, we have an interesting notation to define the universal
set U in this context. We take U defined by the Kleene closure (*) of the alphabet:
U = {a,b}* = {a,b}¹ = {a,b}° U {a,b}¹ U {a,b}² U...
izo
Answer the following questions.
a) What is the shortest string in the universe for A?
b) How many strings are contained in A?
c) Write the contents of {a,b}⁰ U {a,b}¹ U {a,b}² in roster notation.
d) Write the contents of A x A in roster notation. Note that when pairing up the strings, you are
concatenating the strings. Your final answer should not contain any pairs, only strings, and should
not contain any duplicates. To compute this, you can first compute the Cartesian product as usual,
followed by removing the parentheses and commas.
Expert Solution

This question has been solved!
Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.
This is a popular solution
Trending nowThis is a popular solution!
Step by stepSolved in 2 steps

Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, computer-science and related others by exploring similar questions and additional content below.Similar questions
- Let E={0,1}. Give a regular expression r over Σ such that L(r) = { w in Σ* | (w contains at least 4 symbols, that is, the length of w is at least 4) and (the first symbol of w is different from the last symbol of w) and (interior(w) is vorpal according to the following two definitions)}. For any string y containing at least 4 symbols, let interior (y) be the substring of y obtained by removing the first two symbols and the last two symbols of y. A string x over Σ is called vorpal if x satisfies one or more of the following conditions: • x is made up of exactly k 0-symbols where k modulo 4 is 3 (and no 1-symbols) ● x is made up of at least two 1-symbols (and no 0-symbols) ● x contains 011arrow_forwardGiven the following CFG S → OB A → 1AA|A B → OAA The following strings can be generated except i. 001 ii. 000 iii.0011 iv. 01 O A. i and iii O B. i and ii O C. iv only O D. ii onlyarrow_forwardRecall a set A is countable if |N| ≥ |A|. Recall that Cantor’s theorem shows that P(N) = {X ⊆ N}is uncountable. We will show that F = {X ⊆ N | |X| < ∞} is countable, with an onto functiong : N → F that is computable.Write a program/function (e.g., in Python) that runs forever and prints every element of F,e.g., if run it would print something like{0}{1}{0,2}{3}{0,2}{0,5,7}{1}{0,1}{}{2}...(Note that you must prove that the program works, i.e., it prints every element of F, and onlyelements of F.)arrow_forward
- Let ∑ = {a, b}. Given the language L = {b^n a^m: m,n≥0}, find the regular expression r such that L(r) = L.arrow_forwardConsider a set P of points in the plane. Each point is given as a list of two elements [x,y], where x and y are integers. The set Pis given as apython list of points. For example P = [[1,2] , [2,6] , [3,3], [6,1], [2,2]]. A point [x,y] is a super point of P if there does not exist another point [u,v] in P with u > x AND v > y. Define a function (procedure) called super () that takes one parameter, which is a set of points as de- scribed above, and modifies the point set (python list) by removing all elements which represent points that are not super. This function should not include a return statement. After running super (P), the el- ements remaining in P should be in their original order. For example, after running super () then P = [[2,6], [3,3], [6,1]].arrow_forwardGiven a list of rational numbers,find their product. ConceptThe reduce() function applies a function of two arguments cumulatively on a list of objects in succession from left to right to reduce it to one value. Say you have a list, say [1,2,3] and you have to find its sum. >>>reduce(lambdax,y:x+y,[1,2,3])6 You can also define an initial value. If it is specified, the function will assume initial value as the value given, and then reduce. It is equivalent to adding the initial value at the beginning of the list. For example: >>>reduce(lambdax,y:x+y,[1,2,3],-3)3>>>fromfractionsimportgcd>>>reduce(gcd,[2,4,8],3)1 Input Format First line contains , the number of rational numbers.The of next lines contain two integers each, the numerator( ) and denominator( ) of the rational number in the list. Constraints Output Format Print only one line containing the numerator and denominator of the product of the numbers in the list…arrow_forward
- Let Σ={0,1}. Give a regular expression r over Σ such that L(r) = { w in Σ* | (w contains at least 2 symbols, that is, the length of w is at least 2) and (the first symbol of w is different from the last symbol of w) and (centre (w) is mimsy according to the following two definitions)}. For any string y containing at least 2 symbols, let centre (y) be the substring of y obtained by removing the first symbol and the last symbol of y. A string x over Σ is called mimsy if x is made up of either • at least two 0-symbols (and no 1-symbols), or an even number of 1-symbols (and no 0-symbols).arrow_forwardFind all strings in L(ba + ab*a) of length less than four. Find a regular expression for the set { a" bm : n, m are even}.arrow_forwardLet E= {0,1}. Give a regular expression r over Σ such that L(r) = { w in Σ* | (w contains at least 2 symbols, that is, the length of w is at least 2) and (the first symbol of w is different from the last symbol of w) and (centre (w) is mimsy according to the following two definitions)}. For any string y containing at least 2 symbols, let centre (y) be the substring of y obtained by removing the first symbol and the last symbol of y. A string x over Σ is called mimsy if x is made up of either • at least two 0-symbols (and no 1-symbols), or • an even number of 1-symbols (and no 0-symbols).arrow_forward
arrow_back_ios
arrow_forward_ios
Recommended textbooks for you
- Database System ConceptsComputer ScienceISBN:9780078022159Author:Abraham Silberschatz Professor, Henry F. Korth, S. SudarshanPublisher:McGraw-Hill EducationStarting Out with Python (4th Edition)Computer ScienceISBN:9780134444321Author:Tony GaddisPublisher:PEARSONDigital Fundamentals (11th Edition)Computer ScienceISBN:9780132737968Author:Thomas L. FloydPublisher:PEARSON
- C How to Program (8th Edition)Computer ScienceISBN:9780133976892Author:Paul J. Deitel, Harvey DeitelPublisher:PEARSONDatabase Systems: Design, Implementation, & Manag...Computer ScienceISBN:9781337627900Author:Carlos Coronel, Steven MorrisPublisher:Cengage LearningProgrammable Logic ControllersComputer ScienceISBN:9780073373843Author:Frank D. PetruzellaPublisher:McGraw-Hill Education

Database System Concepts
Computer Science
ISBN:9780078022159
Author:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan
Publisher:McGraw-Hill Education

Starting Out with Python (4th Edition)
Computer Science
ISBN:9780134444321
Author:Tony Gaddis
Publisher:PEARSON

Digital Fundamentals (11th Edition)
Computer Science
ISBN:9780132737968
Author:Thomas L. Floyd
Publisher:PEARSON

C How to Program (8th Edition)
Computer Science
ISBN:9780133976892
Author:Paul J. Deitel, Harvey Deitel
Publisher:PEARSON

Database Systems: Design, Implementation, & Manag...
Computer Science
ISBN:9781337627900
Author:Carlos Coronel, Steven Morris
Publisher:Cengage Learning

Programmable Logic Controllers
Computer Science
ISBN:9780073373843
Author:Frank D. Petruzella
Publisher:McGraw-Hill Education