68 research outputs found
Epistemic systems and Flagg and Friedman's translation
In 1986, Flagg and Friedman \cite{ff} gave an elegant alternative proof of
the faithfulness of G\"{o}del (or Rasiowa-Sikorski) translation
of Heyting arithmetic to Shapiro's epistemic arithmetic . In
\S 2, we shall prove the faithfulness of without using
stability, by introducing another translation from an epistemic system to
corresponding intuitionistic system which we shall call \it the modified
Rasiowa-Sikorski translation\rm . That is, this introduction of the new
translation simplifies the original Flagg and Friedman's proof. In \S 3, we
shall give some applications of the modified one for the disjunction property
() and the numerical existence property () of
Heyting arithmetic. In \S 4, we shall show that epistemic Markov's rule
in is proved via . So and are equivalent. In \S 5, we
shall give some relations among the translations treated in the previous
sections. In \S 6, we shall give an alternative proof of Glivenko's theorem. In
\S 7, we shall propose several(modal-)epistemic versions of Markov's rule for
Horsten's modal-epistemic arithmetic . And, as in \S 4, we shall study
some meta-implications among those versions of Markov's rules in and
one in . Friedman and Sheard gave a modal analogue (i.e.
Theorem in \cite{fs}) of Friedman's theorem (i.e. Theorem 1 in
\cite {friedman}): \it Any recursively enumerable extension of which
has also has \rm . In \S 8, we shall give a proof
of our \it Fundamental Conjecture \rm proposed in Inou\'{e}
\cite{ino90a} as follows: This is a new type of proofs. In \S 9, I
shall give discussions.Comment: 33 page
Deciding regular grammar logics with converse through first-order logic
We provide a simple translation of the satisfiability problem for regular
grammar logics with converse into GF2, which is the intersection of the guarded
fragment and the 2-variable fragment of first-order logic. This translation is
theoretically interesting because it translates modal logics with certain frame
conditions into first-order logic, without explicitly expressing the frame
conditions.
A consequence of the translation is that the general satisfiability problem
for regular grammar logics with converse is in EXPTIME. This extends a previous
result of the first author for grammar logics without converse. Using the same
method, we show how some other modal logics can be naturally translated into
GF2, including nominal tense logics and intuitionistic logic.
In our view, the results in this paper show that the natural first-order
fragment corresponding to regular grammar logics is simply GF2 without extra
machinery such as fixed point-operators.Comment: 34 page
Quick cut-elimination for strictly positive cuts
AbstractIn this paper we show that the intuitionistic theory ID̂<ωi(SP) for finitely many iterations of strictly positive operators is a conservative extension of Heyting arithmetic. The proof is inspired by the quick cut-elimination due to G. Mints. This technique is also applied to fragments of Heyting arithmetic
Two kinds of procedural semantics for privative modification
In this paper we present two kinds of procedural semantics for privative modification. We do this for three reasons. The first reason is to launch a tough test case to gauge the degree of substantial agreement between a constructivist and a realist interpretation of procedural semantics; the second is to extend Martin-L ̈f’s Constructive Type Theory to privative modification, which is characteristic of natural language; the third reason is to sketch a positive characterization of privation
Bounded-analytic sequent calculi and embeddings for hypersequent logics
A sequent calculus with the subformula property has long been recognised as a highly favourable starting point for the proof theoretic investigation of a logic. However, most logics of interest cannot be presented using a sequent calculus with the subformula property. In response, many formalisms more intricate than the sequent calculus have been formulated. In this work we identify an alternative: retain the sequent calculus but generalise the subformula property to permit specific axiom substitutions and their subformulas. Our investigation leads to a classification of generalised subformula properties and is applied to infinitely many substructural, intermediate, and modal logics (specifically: those with a cut-free hypersequent calculus). We also develop a complementary perspective on the generalised subformula properties in terms of logical embeddings. This yields new complexity upper bounds for contractive-mingle substructural logics and situates isolated results on the so-called simple substitution property within a general theory
Frege systems for quantified Boolean logic
We define and investigate Frege systems for quantified Boolean formulas (QBF). For these new proof systems, we develop a lower bound technique that directly lifts circuit lower bounds for a circuit class C to the QBF Frege system operating with lines from C. Such a direct transfer from circuit to proof complexity lower bounds has often been postulated for propositional systems but had not been formally established in such generality for any proof systems prior to this work. This leads to strong lower bounds for restricted versions of QBF Frege, in particular an exponential lower bound for QBF Frege systems operating with AC0[p] circuits. In contrast, any non-trivial lower bound for propositional AC0[p]-Frege constitutes a major open problem. Improving these lower bounds to unrestricted QBF Frege tightly corresponds to the major problems in circuit complexity and propositional proof complexity. In particular, proving a lower bound for QBF Frege systems operating with arbitrary P/poly circuits is equivalent to either showing a lower bound for P/poly or for propositional extended Frege (which operates with P/poly circuits). We also compare our new QBF Frege systems to standard sequent calculi for QBF and establish a correspondence to intuitionistic bounded arithmetic.This research was supported by grant nos. 48138 and 60842 from the John Templeton Foundation, EPSRC grant
EP/L024233/1, and a Doctoral Prize Fellowship from EPSRC (third author). The second author was funded by the European
Research Council under the European Union’s Seventh Framework Programme (FP7/2007–2013)/ERC grant agreement
no. 279611 and under the European Union’s Horizon 2020 Research and Innovation Programme/ERC grant agreement no.
648276 AUTAR. The fourth author was supported by the Austrian Science Fund (FWF) under project number P28699 and by
the European Research Council under the European Union’s Seventh Framework Programme (FP7/2007-2014)/ERC Grant
Agreement no. 61507.
Part of this work was done when Beyersdorff and Pich were at the University of Leeds and Bonacina at Sapienza University
Rome.Peer ReviewedPostprint (published version
- …