Path: csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!feeder.erje.net!eu.feeder.erje.net!eternal-september.org!feeder.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: Marko Rauhamaa Newsgroups: comp.lang.python Subject: Re: I have tried and errored a reasonable amount of times Date: Wed, 03 Sep 2014 10:44:34 +0300 Organization: A noiseless patient Spider Lines: 17 Message-ID: <87a96hcfml.fsf@elektro.pacujo.net> References: <5406726f$0$6512$c3e8da3$5496439d@news.astraweb.com> <4af60c7a-f4d6-4aa7-b181-fe768ea6f731@googlegroups.com> <5406c052$0$29876$c3e8da3$5496439d@news.astraweb.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Injection-Info: mx05.eternal-september.org; posting-host="ff5cf27ef3d5b31f034d3b72bdc27a41"; logging-data="11259"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1/YeSJ6fBAIQMOr8ciyuIfw" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.3 (gnu/linux) Cancel-Lock: sha1:ai1Bo09Swo7wC6JANgg51SvpG+w= sha1:TN3MbQqvDui/JHY09iVG3NvH+rU= Xref: csiph.com comp.lang.python:77472 Steven D'Aprano : > Who uses + for disjunction (∨ OR) and concatenation for conjunction (∧ > AND)? That's crazy notation. That's the classic Boolean algebraic notation. In basic algebra, the two interesting operations are "addition" and "multiplication". Boolean math works like elementary arithmetics, with the exception that 1 + 1 = 1 I'm guessing the modern symbols ∨ and ∧ were derived from the set-theoretical analogues, ∪ and ∩, which were also formerly used for the same purpose. Marko