Path: csiph.com!fu-berlin.de!uni-berlin.de!not-for-mail From: Ian Kelly Newsgroups: comp.lang.python Subject: Re: Loop awareness Date: Mon, 29 Feb 2016 13:31:56 -0700 Lines: 13 Message-ID: References: <205018d7-f74d-4fbb-88e1-90c58200486a@googlegroups.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-Trace: news.uni-berlin.de XhVuGPwHYcNzlDwc8AEmVAtE5O5SoYMz/fgUO1G0/R4g== Return-Path: X-Original-To: python-list@python.org Delivered-To: python-list@mail.python.org X-Spam-Status: OK 0.031 X-Spam-Evidence: '*H*': 0.94; '*S*': 0.00; 'problem?': 0.07; '2016': 0.16; 'exhausted': 0.16; 'generated,': 0.16; 'loops': 0.16; 'received:io': 0.16; 'received:psf.io': 0.16; 'wrote:': 0.16; 'creates': 0.18; 'input': 0.18; 'feb': 0.23; 'header:In-Reply- To:1': 0.24; 'mon,': 0.24; 'message-id:@mail.gmail.com': 0.27; 'received:209.85.213.174': 0.29; 'subset': 0.29; 'url:se': 0.29; 'random': 0.29; "can't": 0.32; 'knows': 0.32; 'related': 0.32; 'problem': 0.33; 'values.': 0.33; 'received:google.com': 0.35; 'done': 0.35; 'but': 0.36; 'possible.': 0.36; 'received:209.85': 0.36; 'to:addr:python-list': 0.36; 'pm,': 0.36; 'subject:: ': 0.37; 'received:209.85.213': 0.37; 'no,': 0.38; 'received:209': 0.38; 'to:addr:python.org': 0.40; 'ever': 0.60; 'determine': 0.61; 'necessarily': 0.63; 'to:name:python': 0.84 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:from:date:message-id:subject:to; bh=jJCbCMhTBgG7OUrPAcJ5NFJ6EupxA4FuBVJ9MJH2xhU=; b=vKpKCytsF58/yTDX2VpqHNAvKrzN8pgXtUH3Ca2b1GEMZ4RswK16xJMcs85EjrpVtp bgB8C4w9XruLlE7eQH8m5N3OAbA3M4yttOCHmeAqnjt4wNiccPB632caHDJhTR5r5n8K JlrXEQf+TkOdZ27eEVX3LQSrszApv3pXwC++wHf0UCKjv2d5zYlcIMB9BK7NdQFtCQms 0ebKlpyEuNIltglKWSPJpnkoHAQiGmE/Xy3dDWF7KTXXTDVOK5UbfvnuAkm1gcreZMwu 1psIrA8v7cV+4zeI7YQhOBVJMFPiofk26RFC8xh2QtBncrQOEJO2adjD6KDB4+r8j7G/ 6nzA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to; bh=jJCbCMhTBgG7OUrPAcJ5NFJ6EupxA4FuBVJ9MJH2xhU=; b=honCPsmeZ+PY27H82tIuzJElkvFiQVp7fxUf9Aun/WmL5ltbMN3WafJIImlMTUrYAD L0tEqBY8h8TjkPJgn8qcqbloHwHOcxc8HoEuxPttaNmVbO/04l162MJ8lbS+1eOKazIs fKVBl8phBHMgOzqfKYykaicynvI2W8cIoSTeWwnqhuQ5cdrGKTue0nPPQ5c2zuo7ie8t lrMsNILVsvUMs1zuCoT2ojR5nXr4N8nWZ8mG8kMJ3TZbPxLdjtWZCKUr0lpaADedGCe+ FoK7TOs0437AsvruQG3ZYlmSZybSOCQNDXvXbYIDjfoe1hLbjhRFcl6KYjFDKVZ0g9iT rI2w== X-Gm-Message-State: AD7BkJLw3yw1i2QykFrA0SvrISSoQXRF9/hxPJg9uOm60Wg3ClJHEiZarDSMvgS8IxRmfSTMmunVzEirdSALZA== X-Received: by 10.50.61.177 with SMTP id q17mr11335383igr.68.1456777955505; Mon, 29 Feb 2016 12:32:35 -0800 (PST) In-Reply-To: <205018d7-f74d-4fbb-88e1-90c58200486a@googlegroups.com> X-BeenThere: python-list@python.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: General discussion list for the Python programming language List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Xref: csiph.com comp.lang.python:103758 On Mon, Feb 29, 2016 at 1:07 PM, wrote: > This program creates a uniform linktree of x nodes, and it knows when it get stuck in a loop generating random values. > > Because the networks random generated, only a subset of the permutations will generate a uniform network most get stuck in loops generating random values. But the program keep track the exhausted links and knows when no uniform network possible. > > Is this related to the halting problem? > > http://jt.node365.se/mydebug1.html No, the halting problem is that you can't algorithmically determine whether an *arbitrary* program given *arbitrary* input will ever halt. When you narrow down the scope of the problem considerably, as you've done here, then it's no longer necessarily undecidable.