5,568 research outputs found
Automated Synthesis of Tableau Calculi
This paper presents a method for synthesising sound and complete tableau
calculi. Given a specification of the formal semantics of a logic, the method
generates a set of tableau inference rules that can then be used to reason
within the logic. The method guarantees that the generated rules form a
calculus which is sound and constructively complete. If the logic can be shown
to admit finite filtration with respect to a well-defined first-order semantics
then adding a general blocking mechanism provides a terminating tableau
calculus. The process of generating tableau rules can be completely automated
and produces, together with the blocking mechanism, an automated procedure for
generating tableau decision procedures. For illustration we show the
workability of the approach for a description logic with transitive roles and
propositional intuitionistic logic.Comment: 32 page
An Abstract Tableau Calculus for the Description Logic SHOI Using UnrestrictedBlocking and Rewriting
Abstract This paper presents an abstract tableau calculus for the description logic SHOI. SHOI is the extension of ALC with singleton concepts, role inverse, transitive roles and role inclusion axioms. The presented tableau calculus is inspired by a recently introduced tableau synthesis framework. Termination is achieved by a variation of the unrestricted blocking mechanism that immediately rewrites terms with respect to the conjectured equalities. This approach leads to reduced search space for decision procedures based on the calculus. We also discuss restrictions of the application of the blocking rule by means of additional side conditions and/or additional premises.
Addition of Sodium Bicarbonate to Irrigation Solution May Assist in Dissolution of Uric Acid Fragments During Ureteroscopy
Introduction: We hypothesized that adding sodium bicarbonate (bicarb) to normal saline (NS) irrigation during ureteroscopy in patients with uric acid (UA) nephrolithiasis may assist in dissolving small stone fragments produced during laser lithotripsy. In vitro testing was performed to determine whether dissolution of UA fragments could be accomplished within 1 hour.
Materials and Methods: In total 100% UA renal calculi were fragmented, filtered, and separated by size. Fragment sizes were <0.5âmm and 0.5 to 1âmm. Similar amounts of stone material were agitated in solution at room temperature. Four solutions were tested (NS, NS +1 ampule bicarb/L, NS +2, NS +3). Both groups were filtered to remove solutions after fixed periods. Filtered specimens were dried and weighed. Fragment dissolution rates were calculated as percent removed per hour. Additional testing was performed to determine whether increasing the temperature of solution affected dissolution rates.
Results: For fragments <0.5âmm, adding 2 or 3 bicarb ampules/L NS produced a dissolution rate averaging 91%â±â29% per hour. This rate averaged 226% faster than NS alone. With fragments 0.5 to 1âmm, addition of 2 or 3 bicarb ampules/L NS yielded a dissolution rate averaging 22%â±â7% per hour, which was nearly five times higher than NS alone. There was a trend for an increase in mean dissolution rate with higher temperature but this increase was not significant (pâ=â0.30).
Conclusions: The addition of bicarbonate to NS more than doubles the dissolution rate of UA stone fragments and fragments less than 0.5âmm can be completely dissolved within 1 hour. Addition of bicarb to NS irrigation is a simple and inexpensive approach that may assist in the dissolution of UA fragments produced during ureteroscopic laser lithotripsy. Further studies are needed to determine whether a clinical benefit exists
Hypertableau Reasoning for Description Logics
We present a novel reasoning calculus for the description logic SHOIQ^+---a
knowledge representation formalism with applications in areas such as the
Semantic Web. Unnecessary nondeterminism and the construction of large models
are two primary sources of inefficiency in the tableau-based reasoning calculi
used in state-of-the-art reasoners. In order to reduce nondeterminism, we base
our calculus on hypertableau and hyperresolution calculi, which we extend with
a blocking condition to ensure termination. In order to reduce the size of the
constructed models, we introduce anywhere pairwise blocking. We also present an
improved nominal introduction rule that ensures termination in the presence of
nominals, inverse roles, and number restrictions---a combination of DL
constructs that has proven notoriously difficult to handle. Our implementation
shows significant performance improvements over state-of-the-art reasoners on
several well-known ontologies
From moral welfarism to technical non-welfarism : A step back to Benthamâs felicific calculus of its members
A focus on the information used in Benthamâs felicific calculus sheds new light on the contemporary debate in normative economics opposing non-welfarism to welfarism. As a utilitarian, Bentham is de facto welfarist on a moral sense. Unexpectedly, this study shows Bentham resorts to non-welfarist information in his calculus. Thus, technical non-welfarism is coherent with moral welfarism, and even, the former proves necessary not to betray utilitarian principles. To sustain this claim, we challenge a view opposing a âcardinalâ to an âordinalâ calculus: these two calculi constitute different stages of a unique calculus; because of operational constraints, Bentham is bound to rely on proxies, hence on non-utility information.Bentham, individual utility, utility calculus, utilitarianism, welfarism, non-welfarism, social welfare, technical welfarism, moral welfarism.
Proof Theory of Finite-valued Logics
The proof theory of many-valued systems has not been investigated to an extent comparable to the work done on axiomatizatbility of many-valued logics. Proof theory requires appropriate formalisms, such as sequent calculus, natural deduction, and tableaux for classical (and intuitionistic) logic. One particular method for systematically obtaining calculi for all finite-valued logics was invented independently by several researchers, with slight variations in design and presentation. The main aim of this report is to develop the proof theory of finite-valued first order logics in a general way, and to present some of the more important results in this area. In Systems covered are the resolution calculus, sequent calculus, tableaux, and natural deduction. This report is actually a template, from which all results can be specialized to particular logics
Elimination of Cuts in First-order Finite-valued Logics
A uniform construction for sequent calculi for finite-valued first-order logics with distribution quantifiers is exhibited. Completeness, cut-elimination and midsequent theorems are established. As an application, an analog of Herbrandâs theorem for the four-valued knowledge-representation logic of Belnap and Ginsberg is presented. It is indicated how this theorem can be used for reasoning about knowledge bases with incomplete and inconsistent information
From Logical Calculus to Logical FormalityâWhat Kant Did with Eulerâs Circles
John Venn has the âuneasy suspicionâ that the stagnation in mathematical logic between J. H. Lambert and George Boole was due to Kantâs âdisastrous effect on logical method,â namely the âstrictest preservation [of logic] from mathematical encroachment.â Kantâs actual position is more nuanced, however. In this chapter, I tease out the nuances by examining his use of Leonhard Eulerâs circles and comparing it with Eulerâs own use. I do so in light of the developments in logical calculus from G. W. Leibniz to Lambert and Gottfried Ploucquet. While Kant is evidently open to using mathematical tools in logic, his main concern is to clarify what mathematical tools can be used to achieve. For without such clarification, all efforts at introducing mathematical tools into logic would be blind if not complete waste of time. In the end, Kant would stress, the means provided by formal logic at best help us to express and order what we already know in some sense. No matter how much mathematical notations may enhance the precision of this function of formal logic, it does not change the fact that no truths can, strictly speaking, be revealed or established by means of those notations
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