From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=5.0 tests=DKIM_INVALID,DKIM_SIGNED, MAILING_LIST_MULTI autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 7744 invoked from network); 2 Mar 2023 02:12:26 -0000 Received: from minnie.tuhs.org (50.116.15.146) by inbox.vuxu.org with ESMTPUTF8; 2 Mar 2023 02:12:26 -0000 Received: from minnie.tuhs.org (localhost [IPv6:::1]) by minnie.tuhs.org (Postfix) with ESMTP id 30D0F43604; Thu, 2 Mar 2023 12:12:22 +1000 (AEST) Received: from mail-pl1-x635.google.com (mail-pl1-x635.google.com [IPv6:2607:f8b0:4864:20::635]) by minnie.tuhs.org (Postfix) with ESMTPS id 766E343603 for ; Thu, 2 Mar 2023 12:12:14 +1000 (AEST) Received: by mail-pl1-x635.google.com with SMTP id z2so16031689plf.12 for ; Wed, 01 Mar 2023 18:12:14 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=iitbombay-org.20210112.gappssmtp.com; s=20210112; h=to:references:message-id:content-transfer-encoding:cc:date :in-reply-to:from:subject:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=Sa3zW2G8nVyOIUpxTCV8AoG0+UfqOhmZhrD+WqFNB9g=; b=tyh/nj09EZZHke0M7PvshuykJEwZBUYMQ5B6pDn8rtjkqLJW7I2p1ay4pn5tWFpbMp 3YDXDzObiduytBTf94c0Ty2FF9Zhcb/xT9jBNG2iRN09CXTq1fkGp9g2yTQ5UxUiW6eD 8r2eieMOuRVM6WOIRvAkc6GIgTer4mpIr4Bb7M3zxZTWM3YeUUvPpoN10muRexgISUKe wsE9NK1CE21ka04yotavy30DQSwCvrsO94dMev6sqK0IquC9MXFkjUeLAdknoQK7WL1m JaMWh2k2mC52s3/1dSIsFVbjQe8adB8H6eNrTOD4YVYFS2aF4t+xvHIpy3HwfuwNi7kG S46w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=to:references:message-id:content-transfer-encoding:cc:date :in-reply-to:from:subject:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=Sa3zW2G8nVyOIUpxTCV8AoG0+UfqOhmZhrD+WqFNB9g=; b=10DO0d4pNG7AywIGDF4ex5Xh4tvyxwa9mrK3/B1S9aGuE0H+TZbHUsgx0WjbHKGVHp lfBr9zOGwZU+XDo+TcNIl+Esf5C9ed39M0bxZRJflunQpGIKYc6ESCnrLjeWDafHqjGp gAjriBgXswtvj4xmu3TNqJGcEcCJIWsSHcJtTyJJwl9eIss4cjKa/6K0a5isgqA2y/1F vJUJDIzKBYMSO3QJvwFlP+jSqA9T5OLE6kFMwUAoRGjXElts4ZFQVEqq4Q34p8IWDBcp sqGT24F8T0Bl0OodFt81i+yJB7ixA5G9s7TJAK+p71ea9lmZmdXz/IS1HvSTTMvCJq+9 9kTQ== X-Gm-Message-State: AO0yUKVXRCWeqm2lxJ8p8zp3Hco0jDKCgWVYoWt/EyiKrcNQuTDDybol Dg7IPloaQgUL0M/7OGKO0LpNtXTKd57M67JQ X-Google-Smtp-Source: AK7set/PUceHpnBhzuGG347scizRtKGhAaLzXEkgxnU888pH3xW5z/QNU7gfFy0erxDWbTAYKUZc9w== X-Received: by 2002:a17:902:d4c1:b0:19c:c184:d211 with SMTP id o1-20020a170902d4c100b0019cc184d211mr11109764plg.37.1677723133742; Wed, 01 Mar 2023 18:12:13 -0800 (PST) Received: from smtpclient.apple (107-215-223-229.lightspeed.sntcca.sbcglobal.net. [107.215.223.229]) by smtp.gmail.com with ESMTPSA id iy12-20020a170903130c00b00183c6784704sm9090781plb.291.2023.03.01.18.12.13 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Wed, 01 Mar 2023 18:12:13 -0800 (PST) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3731.400.51.1.1\)) From: Bakul Shah In-Reply-To: <20230302013628.8E40618C07B@mercury.lcs.mit.edu> Date: Wed, 1 Mar 2023 18:12:02 -0800 Content-Transfer-Encoding: quoted-printable Message-Id: References: <20230302013628.8E40618C07B@mercury.lcs.mit.edu> To: Noel Chiappa X-Mailer: Apple Mail (2.3731.400.51.1.1) Message-ID-Hash: GXYHHEUYK5D3CKXV3VW2PE6Q4MWLD2UY X-Message-ID-Hash: GXYHHEUYK5D3CKXV3VW2PE6Q4MWLD2UY X-MailFrom: bakul@iitbombay.org X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: tuhs@tuhs.org X-Mailman-Version: 3.3.6b1 Precedence: list Subject: [TUHS] Re: Unix v7 icheck dup problem List-Id: The Unix Heritage Society mailing list Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: On Mar 1, 2023, at 5:36 PM, Noel Chiappa = wrote: >=20 > Steve Ward told another oral story which I'm pretty sure _is_ true, = though. > They ask the candidate to design a state machine (or digital logic, I = forget > which) which can tell if a number is divisible by three (I think I = have the > details correct, but I'm not absolutely certain). So they describe one = - and > then point out that you can feed the number in from either end (most = or least > significant end first) - and proves that it will work either way! The > committee was blown away. Doesn't everyone know that a number is divisible by 3 if the one digit result after casting out 9s is divisible by 3?=