Path: ...!weretis.net!feeder8.news.weretis.net!reader5.news.weretis.net!news.solani.org!.POSTED!not-for-mail From: Mild Shock Newsgroups: sci.logic Subject: Re: Advent of Logic 2024: Specification and Deadline (Was: Advent of Logic 2024: Weekend 1) Date: Fri, 20 Dec 2024 02:48:55 +0100 Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Fri, 20 Dec 2024 01:48:55 -0000 (UTC) Injection-Info: solani.org; logging-data="1605642"; 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/2.53.19 Cancel-Lock: sha1:d1PINzKU40ORciUOANnPqDDeMzY= In-Reply-To: X-User-ID: eJwNwoERwCAIBLCVRJ5HxgHB/UdoLzGl8DpohL0fAutwvDzS34tKZRu3yAwmZ1KqtS5tQrHzUnvhFLrU1D9aPhXI Bytes: 2774 Lines: 55 Its quite intersting that Affine Logic can be measured by the realization of this output: > - Output = Variable % Repetition Its seems to me that in Affine Logic a variable is only allowed to occur in a Repetition at most once, it seems also to me that each variable must be also repeated at least once. So that variables are repreated exactly once. Here is a counter example with too many repetitions, this would not be a valid output for weekend 3, since it cannot be converted into the output of weekend 2: λx:A->A.λy:A.(x (x y)) : ((A -> A) -> (A -> A)) And her is a counter example with too few repetitions, equally well it cannot be converted to a BCI expression. λx:A.λy:B.x : (A -> (B -> A)) I tried it heuristically, Affine Logic can indeed not prove (A -> (B -> A)). Don't know yet how to show it rigorously, this would need some model theory. Mild Shock schrieb: > Specification: > > > Weekend 2: > ----------- > - Input = Atom            % Propositional variable >         | Input -> Input  % Implication > > - Output = B               % B Axiom Schema >          | C               % C Axiom Schema >          | I               % I Axiom Schema >          | (Output Output) % Modus Ponens > > Weekend 3: > ----------- > - Input = Atom            % Propositional variable >         | Input -> Input  % Implication > > - Output = Variable         % Repetition >          | λVariable.Output % Assumption & Detachment >          | (Output Output)  % Modus Ponens > > > Deadline: > > 24. December 2024 >