The correct statements are: If L₁ and L₂ are not regular languages, then L₁ U L₂ cannot be regular. If L₁ and L₂ are regular languages, then L₁ L₂ = {w: w€ (L₁-L₂) or w€ (L₂ - L₁)} is regular. It is possible that the union of a regular language and a nonregular language is regular. Every subset of a regular language is regular.

The correct statements are: If L₁ and L₂ are not regular languages, then L₁ U L₂ cannot be regular. If L₁ and L₂ are regular languages, then L₁ L₂ = {w: w€ (L₁-L₂) or w€ (L₂ - L₁)} is regular. It is possible that the union of a regular language and a nonregular language is regular. Every subset of a regular language is regular.

Database System Concepts

7th Edition

ISBN:9780078022159

Author:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Publisher:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Chapter1: Introduction

Section: Chapter Questions

Problem 1PE

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Predicates

A predicate is a function defined with set of variables, which returns the result True or False. The output of a predicate is a Boolean value as a response when given a set of parameters:

Question

The correct statements are:
If L₁ and L2 are not regular languages, then L₁ U L₂ cannot be regular.
If L₁ and L₂ are regular languages, then L₁ L₂ = {w: w€ (L₁-L₂) or w€ (L₂-L₁)} is regular.
It is possible that the union of a regular language and a nonregular language is regular.
Every subset of a regular language is regular.

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