Path: ...!feeds.phibee-telecom.net!news.mixmin.net!weretis.net!feeder8.news.weretis.net!reader5.news.weretis.net!news.solani.org!.POSTED!not-for-mail From: Mild Shock Newsgroups: comp.theory,sci.logic Subject: "undecidable" / "unentscheidbar" (Was Analytic Truth-makers) Date: Tue, 23 Jul 2024 23:02:01 +0200 Message-ID: References: <3fb77583036a3c8b0db4b77610fb4bf4214c9c23@i2pn2.org> <9577ce80fd6c8a3d5dc37b880ce35a4d10d12a0e@i2pn2.org> <7d9b88425623e1166e358f1bce4c3a2767c36da0@i2pn2.org> <2a0f9a4235d75dee94ccae62b10d3afef5a966a5@i2pn2.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Tue, 23 Jul 2024 21:01:58 -0000 (UTC) Injection-Info: solani.org; logging-data="274478"; mail-complaints-to="abuse@news.solani.org" User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Firefox/91.0 SeaMonkey/2.53.18.2 Cancel-Lock: sha1:hn4nu1wzWsSncZqIMC0IBnwnh+s= X-User-ID: eJwNyMEBwCAIA8CVVAjqOCSF/Uew9zxYzND2QDgaHXl0dYkah5hdA1i2oEEBO+mqy+3gR3OqZh5rqP5jWT5jKhZ3 In-Reply-To: Bytes: 2624 Lines: 33 For example Gödel belongs to the generation of logicians that use the term "undecidable". In German the term is translated to "unentscheidbar": Über formal unentscheidbare Sätze der Principia Mathematica und verwandter Systeme I" ("On Formally Undecidable Propositions of Principia Mathematica and Related Systems I") https://en.wikipedia.org/wiki/On_Formally_Undecidable_Propositions_of_Principia_Mathematica_and_Related_Systems Mild Shock schrieb: > Since generations logicians have called sentences > which you clumsily call "not a truth-bearer", > simple called "undecidable" sentences. > > A theory is incomplete, if it has undecidable > sentences. There is a small difference between > unprovable and undecidable. > > An unprovable senetence A is only a sentence with: > > ~True(L, A). > > An undecidable sentence A is a sentence with: > > ~True(L, A) & ~True(L, ~A) > > Meaning the sentence itself and its complement > are both unprovable. > > olcott schrieb: >> ~True(L,x) ∧ ~True(L,~x) >> means that x is not a truth-bearer in L. >> It does not mean that L is incomplete