0
votes
2answers
35 views

Gives regular expressions which defines regular language and what does {1,2} mean

The question is give a regular expression which defines a regular language. Question: The language over {0,1} consisting of all strings which either have length less than 3 or have 0 as their third ...
1
vote
1answer
80 views

Finite state machine

I am doing discrete math, and we are studying Finite State Machines. But i am a little confuse on how to do this. Here is a question, Write a regular expression for the language, and define a finite ...
0
votes
3answers
92 views

What is the difference between regex operations in math and regex in UNIX / Linux?

What is the difference between regular expression operations (union, concatenation, kleene star) and regular expression (implemented in UNIX and can be used together with the grep command)? Are there ...
-1
votes
1answer
42 views

Finding the wrong regular expression

Which one of the following regular expressions does not define the language of all strings that ends with a. $(a + b)^*a$ $b^*aa^*(bb^*aa^*)^*$ $[a(ba)^* + b(ab)^*](a + b)^*a$ $(b + aa^*b)^*a(a + ...
0
votes
1answer
45 views

Find Regular Grammar from NFA

I'm currently doing some self study to improve my half-forgotten college theory of comp skills. I'm going over some problems from an old book and it asks you to find a regular grammar for the ...
0
votes
1answer
192 views

What can be defined as a Regular Set

I'm currently studying compilers and am having some issues with understanding regular sets. For example, lets say I had a set of binary strings, (0, 1). Would all integers that are even and positive ...
1
vote
1answer
85 views

Give a regular grammar for L

Give a regular grammar for L= {a^n b^n : n<=100} I would do something like this : S---> A | empty string A---> aB| empty String B---> Ab but How do we keep count of the number in the grammar? ...
1
vote
1answer
312 views

A regular expression for the words that don't contain the sequence $ab$ over $\{a,b,c\}$

The following is an exercise in a book I am reading: Let $\Sigma=\{a,b,c\}$, define $L$ to be the language of all words over $\Sigma$ that do not contain $ab$ as a sub-word. Find a regular ...
0
votes
1answer
72 views

Regular expression arithmetics

What are the rules of regular expression arithmetics ? For example: Let $\Sigma=\{0,1\}$ $1. 1+01=(\epsilon+0)1$. $2. (\epsilon+00)^*=(00)^*$