Path: ...!eternal-september.org!feeder2.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: WM Newsgroups: sci.math Subject: Re: How many different unit fractions are lessorequal than all unit fractions? (infinitary) Date: Mon, 4 Nov 2024 12:07:35 +0100 Organization: A noiseless patient Spider Lines: 13 Message-ID: References: <30dffbdf129483f7b61e3284d1e7bf2ad2e5ea16@i2pn2.org> <9ca97f4a24ae1e3041583265125cf860d2fada11@i2pn2.org> <6ed3abd1b4d30ed6db4b9152f7a0ad5da583f147@i2pn2.org> <9a16dc217c4a1833dd297216773623a70ad06a10@i2pn2.org> <9aee86160da6eb1d047509ca9f0a82344039a4e9@i2pn2.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Mon, 04 Nov 2024 12:07:35 +0100 (CET) Injection-Info: dont-email.me; posting-host="10c225c131b9f83ecf8835aacca35945"; logging-data="950406"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1+jPUqaiDPPN5xetiv4ewYzKJFn6+Xf45c=" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:jMwonODhkGkHzhEZ+xBEZcx+jsM= In-Reply-To: <9aee86160da6eb1d047509ca9f0a82344039a4e9@i2pn2.org> Content-Language: en-US Bytes: 2435 On 03.11.2024 22:21, Richard Damon wrote: > But Induction *IS* valid for all Natural Numbers. Only for all natnumbers which can be defined and which belong to a finite initial segment which is followed by ℵo natnumbers most of which you cannot define. By induction you can prove the sum n(n+1)/2 for every initial segment 1+2+3+...+n. But not for all natural numbers. Regards, WM