Bem, certamente os nossos colegas estão precisando menos da nossa *confiança* na correção do resultado e mais da *leitura competente* do material que produziram...
A propósito, Hermann pediu para avisar que a página http://www.tecmf.inf.puc-rio.br/NPPSPACE foi atualizada com material explicativo, e para dizer que "há alguns problemas de formatação (código tex misturado com wiki), mas é perfeitamente inteligível". JM >>> ---------- Forwarded message ---------- >>> >>> Date: Sat, 8 Oct 2016 10:06:50 -0600 >>> From: Richard Zach <rz...@ucalgary.ca> >>> To: <f...@cs.nyu.edu> >>> >>> >>> New on arXiv this week; has anyone read it/formed an opinion? >>> >>> https://arxiv.org/abs/1609.09562 >>> >>> NP vs PSPACE >>> Lew Gordeev <https://arxiv.org/find/cs/1/au:+Gordeev_L/0/1/0/all/0/1>, >>> Edward Hermann Haeusler >>> <https://arxiv.org/find/cs/1/au:+Haeusler_E/0/1/0/all/0/1> >>> (Submitted on 30 Sep 2016) >>> >>> We present a proof of the conjecture $\mathcal{NP}$ = >>> $\mathcal{PSPACE}$ by showing that arbitrary tautologies of >>> Johansson's minimal propositional logic admit "small" polynomial-size >>> dag-like natural deductions in Prawitz's system for minimal >>> propositional logic. These "small" deductions arise from standard >>> "large"\ tree-like inputs by horizontal dag-like compression that is >>> obtained by merging distinct nodes labeled with identical formulas >>> occurring in horizontal sections of deductions involved. The >>> underlying "geometric" idea: if the height, $h\left( \partial \right) >>> $ , and the total number of distinct formulas, $\phi \left( \partial >>> \right) $ , of a given tree-like deduction $\partial$ of a minimal >>> tautology $\rho$ are both polynomial in the length of $\rho$, $\left| >>> \rho \right|$, then the size of the horizontal dag-like compression is >>> at most $h\left( \partial \right) \times \phi \left( \partial \right) >>> $, and hence polynomial in $\left| \rho \right|$. The attached proof >>> is due to the first author, but it was the second author who proposed >>> an initial idea to attack a weaker conjecture $\mathcal{NP}= >>> \mathcal{\mathit{co}NP}$ by reductions in diverse natural deduction >>> formalisms for propositional logic. That idea included interactive use >>> of minimal, intuitionistic and classical formalisms, so its practical >>> implementation was too involved. The attached proof of $ >>> \mathcal{NP}=\mathcal{PSPACE}$ runs inside the natural deduction >>> interpretation of Hudelmaier's cutfree sequent calculus for minimal >>> logic. -- Você está recebendo esta mensagem porque se inscreveu no grupo "LOGICA-L" dos Grupos do Google. Para cancelar inscrição nesse grupo e parar de receber e-mails dele, envie um e-mail para logica-l+unsubscr...@dimap.ufrn.br. Para postar neste grupo, envie um e-mail para logica-l@dimap.ufrn.br. Visite este grupo em https://groups.google.com/a/dimap.ufrn.br/group/logica-l/. Para ver esta discussão na web, acesse https://groups.google.com/a/dimap.ufrn.br/d/msgid/logica-l/CAO6j_LgdR%2BQkG_6EXQQXdmj0rttxforXPH_u6Hzfs%3DGCj46mVw%40mail.gmail.com.
