Re: [rrg] p=np !
"Leszek T. Lilien" <leszek.lilien@wmich.edu> Wed, 07 September 2011 15:44 UTC
Return-Path: <leszek.lilien@wmich.edu>
X-Original-To: rrg@ietfa.amsl.com
Delivered-To: rrg@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 253CA21F8CA5 for <rrg@ietfa.amsl.com>; Wed, 7 Sep 2011 08:44:07 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -5.627
X-Spam-Level:
X-Spam-Status: No, score=-5.627 tagged_above=-999 required=5 tests=[AWL=0.372, BAYES_00=-2.599, J_CHICKENPOX_12=0.6, RCVD_IN_DNSWL_MED=-4]
Received: from mail.ietf.org ([12.22.58.30]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Ye7kfgnzVh0W for <rrg@ietfa.amsl.com>; Wed, 7 Sep 2011 08:44:03 -0700 (PDT)
Received: from mx-tmp.wmich.edu (mx-tmp.wmich.edu [141.218.1.43]) by ietfa.amsl.com (Postfix) with ESMTP id 4E46A21F8559 for <rrg@irtf.org>; Wed, 7 Sep 2011 08:44:03 -0700 (PDT)
MIME-version: 1.0
Content-transfer-encoding: 8bit
Content-type: text/plain; charset="UTF-8"; format="flowed"
Received: from [192.168.0.199] (adsl-76-235-185-171.dsl.klmzmi.sbcglobal.net [76.235.185.171]) by mta01.service.private (Sun Java(tm) System Messaging Server 6.3-8.01 (built Dec 16 2008; 64bit)) with ESMTPSA id <0LR500BQGT4FHH50@mta01.service.private> for rrg@irtf.org; Wed, 07 Sep 2011 11:45:52 -0400 (EDT)
X-WMU-Spam: Gauge=XXXII, Probability=32% on Wed Sep 7 11:45:52 2011, Report=' WMU_MSA_SMTP+ 0, SXL_IP_DYNAMIC 3, TO_IN_SUBJECT 0.5, BODY_SIZE_3000_3999 0, BODY_SIZE_5000_LESS 0, BODY_SIZE_7000_LESS 0, DATE_TZ_NA 0, FROM_EDU_TLD 0, RDNS_GENERIC_BROADBAND 0, RDNS_GENERIC_POOLED 0, RDNS_SUSP 0, RDNS_SUSP_GENERIC 0, SPF_NEUTRAL 0, __ANY_URI 0, __BOUNCE_CHALLENGE_SUBJ 0, __BOUNCE_NDR_SUBJ_EXEMPT 0, __CP_URI_IN_BODY 0, __CT 0, __CTE 0, __CT_TEXT_PLAIN 0, __FRAUD_BODY_WEBMAIL 0, __FRAUD_REFNUM 0, __FRAUD_WEBMAIL 0, __HAS_MSGID 0, __MIME_TEXT_ONLY 0, __MIME_VERSION 0, __MOZILLA_MSGID 0, __PHISH_SPEAR_STRUCTURE_1 0, __SANE_MSGID 0, __TO_MALFORMED_2 0, __TO_NO_NAME 0, __URI_NS , __USER_AGENT 0'
X-WMU-PMX-Version: 5.5.9.395186, Antispam-Engine: 2.7.2.376379, Antispam-Data: 2011.9.7.153620 - Wed Sep 7 11:45:52 2011
Sender: leszek.lilien@wmich.edu
Message-id: <4E6791AF.3050106@wmich.edu>
Date: Wed, 07 Sep 2011 11:45:51 -0400
From: "Leszek T. Lilien" <leszek.lilien@wmich.edu>
Organization: WMU
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.2.9) Gecko/20100915 Lightning/1.0b2 Thunderbird/3.1.4
To: HeinerHummel@aol.com, rrg@irtf.org
Subject: Re: [rrg] p=np !
X-BeenThere: rrg@irtf.org
X-Mailman-Version: 2.1.12
Precedence: list
Reply-To: leszek.lilien@wmich.edu
List-Id: IRTF Routing Research Group <rrg.irtf.org>
List-Unsubscribe: <http://www.irtf.org/mailman/options/rrg>, <mailto:rrg-request@irtf.org?subject=unsubscribe>
List-Archive: <http://www.irtf.org/mail-archive/web/rrg>
List-Post: <mailto:rrg@irtf.org>
List-Help: <mailto:rrg-request@irtf.org?subject=help>
List-Subscribe: <http://www.irtf.org/mailman/listinfo/rrg>, <mailto:rrg-request@irtf.org?subject=subscribe>
X-List-Received-Date: Wed, 07 Sep 2011 15:44:07 -0000
Dear Heiner, >I wonder why the Traveling Salesman Problem is said to be NP-hard > although it can be solved by Linear Programming ? Wikipedia is not the ultimate authority, but even Wikipedia answers your question (http://en.wikipedia.org/wiki/P_versus_NP_problem): > Because of these factors, even if a problem is shown to be > NP-complete, and even if P ≠ NP, there may still be effective > approaches to tackling the problem in practice. There are algorithms > for many NP-complete problems, such as the knapsack problem, the > travelling salesman problem and the boolean satisfiability problem, > that can solve to optimality many real-world instances in reasonable > time. The empirical average-case complexity (time vs. problem size) > of such algorithms can be surprisingly low. 2) > I am no scientist, Are you an engineer? Then, relying on good references and strong arguments should be a second nature to you as well. I wish I didn't have to say this (but I feel it is a scientist's duty): Making revolutionary claims (like you did by writing: "I like to assure all on this mailing list that P = NP") without a proper proof is not only counterproductive but downright irresponsible. Best regards, Leszek -------- Original Message -------- Subject: Re: [rrg] p=np ! Date: Wed, 07 Sep 2011 04:47:41 -0400 (EDT) From: heinerhummel@aol.com To: leszek.lilien@wmich.edu, rrg@irtf.org I am no scientist, but may be you are ?: I wonder why the Traveling Salesman Problem is said to be NP-hard although it can be solved by Linear Programming ? I appreciate any clarifying info. Heiner -----Ursprüngliche Mitteilung----- Von: Leszek T. Lilien <leszek.lilien@wmich.edu> An: rrg <rrg@irtf.org> Verschickt: Mo, 5 Sept 2011 6:59 pm Betreff: Re: [rrg] p=np ! Heiner, Are you a scientist or not? Your message suggests the latter. (A scientist would vive a proper reference!) Leszek -------- Original Message -------- Subject: Re: [rrg] p=np ! Date: Mon, 05 Sep 2011 16:39:23 -0400 (EDT) From: heinerhummel@aol.com To: jinchoe@gmail.com CC: rrg@irtf.org Sorry, I can't. It is only myself who thinks to have developed a solution for a np-hard problem. Precisely for the Steiner Tree problem. A solution by which any possible lever is applied to improve a current Steiner Tree until no further lever can quench out any more weight reduction of the tree at all. I am not a man the press is interested in. Hence I cannot refer to any press news. Heiner -----Ursprüngliche Mitteilung----- Von: JinHyeock Choi<jinchoe@gmail.com> An: heinerhummel<heinerhummel@aol.com> Cc: rrg<rrg@irtf.org> Verschickt: So, 4 Sept 2011 8:17 pm Betreff: Re: [rrg] p=np ! > I like to assure all on this mailing list that P = NP. You mean it has been proved that P = NP? if so, would you provide a pointer to a relevant article? That could bring forth a huge impact. best regards JinHyeock _______________________________________________ rrg mailing list rrg@irtf.org http://www.irtf.org/mailman/listinfo/rrg
- [rrg] p=np ! heinerhummel
- Re: [rrg] p=np ! JinHyeock Choi
- Re: [rrg] p=np ! Tony Li
- Re: [rrg] p=np ! Michael Hallgren
- Re: [rrg] [ot] p=np ! Sampo Syreeni
- Re: [rrg] p=np ! heinerhummel
- Re: [rrg] p=np ! Leszek T. Lilien
- Re: [rrg] [ot] p=np ! heinerhummel
- Re: [rrg] p=np ! heinerhummel
- Re: [rrg] p=np ! Tony Li
- Re: [rrg] p=np ! Leszek T. Lilien
- Re: [rrg] p=np ! Leszek T. Lilien
- Re: [rrg] p=np ! Tony Li
- Re: [rrg] p=np ! Leszek T. Lilien