The Gateway to Computer Science Excellence
+1 vote
896 views

I) Every language in NP is recursive.

II)Every language in NP is recursively enumerable.

Which of the statements is /are true?

A. I only

B. II only

C. Both I and II

D Neither I nor II

in Theory of Computation by Boss (33k points)
retagged by | 896 views

2 Answers

+2 votes
p⊆Np⊆recursive⊆recursive enumerable

just remember this
by Loyal (5.6k points)
0
0 votes
i think every problem in NP is decidable means it is recursive .and every recursive problem is recursively enumerable so we can say that both are true,correct me if i am wrong ..
by (181 points)
0
yes you are right..!!

answer is C
0

@Sidhi: Sir,

I have a doubt what does "every problem in NP is decidable " means?

What we are deciding for given NP problem?

Are we deciding proposed solution is correct or not?

Or are we deciding whether any solution exists for given problem?

Sorry, if I asked a lame question :P

0
i can't understand what you want to ask exactly..may below link will help you to understand, check it out.

https://www.quora.com/Theoretical-Computer-Science-Are-all-P-languages-decidable-Are-all-NP-languages-decidable
+1

@Sidhi: thanks for that wonderful link.. Concept is pretty clear now!!

  • NP is the class of languages that can be recognized by a non deterministic Turing machine
  • A decidable language is a formal language for which there exists a Turing machine which will, when presented with any finite input string , halt and accept if the string is in the language, and halt and reject otherwise. 
  • Since any language in NP can be recognized by a non deterministic TM,  there is a TM that always halts when presented with any finite input string of the language. 
  • Hence NP is decidable
  •  Since P NPP⊂ NP, any language in P is also decidable.
0
p⊆Np⊆recursive
Quick search syntax
tags tag:apple
author user:martin
title title:apple
content content:apple
exclude -tag:apple
force match +apple
views views:100
score score:10
answers answers:2
is accepted isaccepted:true
is closed isclosed:true
50,737 questions
57,309 answers
198,330 comments
105,019 users