Marcello D'Agostino | Università degli Studi di Milano - State University of Milan (Italy) (original) (raw)

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Papers by Marcello D'Agostino

Artificial Intelligence

A well studied instantiation of Dung's abstract theory of argumentation yields argumentationbased... more A well studied instantiation of Dung's abstract theory of argumentation yields argumentationbased characterisations of non-monotonic inference over possibly inconsistent sets of classical formulae. This provides for single-agent reasoning in terms of argument and counter-argument, and distributed non-monotonic reasoning in the form of dialogues between computational and/or human agents. However, features of existing formalisations of classical logic argumentation (Cl-Arg) that ensure satisfaction of rationality postulates, preclude applications of Cl-Arg that account for real-world dialectical uses of arguments by resource-bounded agents. This paper formalises dialectical classical logic argumentation that both satisfies these practical desiderata and is provably rational. In contrast to standard approaches to Cl-Arg we: 1) draw an epistemic distinction between an argument's premises accepted as true, and those assumed true for the sake of argument, so formalising the dialectical move whereby arguments' premises are shown to be inconsistent, and avoiding the foreign commitment problem that arises in dialogical applications; 2) provide an account of Cl-Arg suitable for real-world use by eschewing the need to check that an argument's premises are subset minimal and consistent, and identifying a minimal set of assumptions as to the arguments that must be constructed from a set of formulae in order to ensure that the outcome of evaluation is rational. We then illustrate our approach with a natural deduction proof theory for propositional classical logic that allows measurement of the 'depth' of an argument, such that the construction of depth-bounded arguments is a tractable problem, and each increase in depth naturally equates with an increase in the inferential capabilities of real-world agents. We also provide a resource-bounded argumentative characterisation of non-monotonic inference as defined by Brewka's Preferred Subtheories.

Scientometrics

In many situations we are interested in appraising the value of a certain characteristic for a gi... more In many situations we are interested in appraising the value of a certain characteristic for a given individual relative to the context in which this value is observed. In recent years this problem has become prominent in the evaluation of scientific productivity and impact. A popular approach to such relative valuations consists in using percentile ranks. This is a purely ordinal method that may sometimes lead to counterintuitive appraisals, in that it discards all information about the distance between the raw values within a given context. By contrast, this information is partly preserved by using standardization, i.e., by transforming the absolute values in such a way that, within the same context, the distance between the relative values is monotonically related to the distance between the absolute ones. While there are many practically useful alternatives for standardizing a given characteristic across different contexts, the general problem seems to have never been addressed from a theoretical and normative viewpoint. The main aim of this paper is to fill this gap and provide a conceptual framework that allows for this kind of systematic investigation. We then use this framework to prove that, under some rather weak assumptions, the general format of a standardization function can be determined quite sharply.

Proceedings of the Twenty-Ninth International Joint Conference on Artificial Intelligence

ASPIC+ is an established general framework for argumentation and non-monotonic reasoning. However... more ASPIC+ is an established general framework for argumentation and non-monotonic reasoning. However, ASPIC+ does not satisfy the non-contamination rationality postulates, and moreover, tacitly assumes unbounded resources when demonstrating satisfaction of the consistency postulates. In this paper we present a new version of ASPIC+ – Dialectial ASPIC+ – that is fully rational under resource bounds.

... HANDBOOK OF TABLEAU METHODS Edited by MARCELLO D'AGOSTINO Universita di ... more ... HANDBOOK OF TABLEAU METHODS Edited by MARCELLO D'AGOSTINO Universita di Ferrara, Ferrara, Italy DOV M. GABBAY King's College, London, United ... ISBN 0-7923-5627-6 Published by Kluwer Academic Publishers, PO Box, 3300 AA Dordrecht, The Netherlands. ...

Lecture Notes in Computer Science, 1998

ABSTRACT WinKE is a new interactive theorem proving assistant based on the KE calculus, a refutat... more ABSTRACT WinKE is a new interactive theorem proving assistant based on the KE calculus, a refutation system which combines features from Smullyan’s analytic tableaux and Gentzen’s natural deduction. It has been developed to support teaching logic and reasoning to undergraduate students. The WinKE process of constructing a proof tree is as faithful as possible to the pen-and-paper procedure. Running under Windows 95, it is easy to use and visually satisfying. The WinKE system features an interactive interface via menus, dialogues, and graphic tools, on- and off-line proof-checking, and is completed by the option to automatically perform proofs (or parts of a proof), and to build up countermodels. User support is provided by bookkeeping facilities, hints, various “undo” utilities, and a detailed on-line help system. The system provides several files with example problems. New ones can be edited directly within WinKE. The interface consists of four windows: the main window providing menus and buttons for quick access to the most basic functions, the graphic window to display and manipulate KE proof trees, a viewer which displays a scaled-down view of the virtual drawing board, allowing to focus on a particular portion of it, and a tool box containing the graphic tools. The design of the interface is close to that of Windows standard software, which makes it very easy to learn how to use the system. WinKE is supportive of an introductory textbook on classical logic, but may also be used independently. References and further information about WinKE as well as the KE calculus can be found at the URL: http://dns.unife.it/dgm/WinKE/.

You are, all of you in this community, brothers. But when god fashioned you, he added gold in the... more You are, all of you in this community, brothers. But when god fashioned you, he added gold in the composition of those of you who are qualified to be Rulers (which is why their prestige is greatest); he put silver in the Auxiliaries, and iron and bronze in the farmers and other workers. Now since you are all of the same stock, though your children will commonly resemble their parents, occasionally a silver child will be born of golden parents, or a golden child of silver parents, and so on. Therefore the first and most important of god's commandments to the Rulers is that in the exercise of their function as Guardians their principal care must be to watch the mixture of metals in the characters of their children. If one of their own children has traces of bronze or iron in its make-up, they must harden their hearts, assign it its proper value, and degrade it to the ranks of the industrial and agricoltural class where it properly belongs: similarly, if a child of this class is b...

Journal of Logic, Language and Information, 1992

We show that Smullyan's analytic tableaux cannot p-simulate the truth-tables. We identify the cau... more We show that Smullyan's analytic tableaux cannot p-simulate the truth-tables. We identify the cause of this computational breakdown and relate it to an underlying semantic difficulty which is common to the whole tradition originating in Gentzen's sequent calculus, namely the dissonance between cut-free proofs and the Principle of Bivalence. Finally we discuss some ways in which this principle can be built into a tableau-like method without affecting its "analytic" nature.

Page 1. APPLIED LOGIC SERI Labelled Deduction David Basin, M arcello D&am... more Page 1. APPLIED LOGIC SERI Labelled Deduction David Basin, M arcello D'Agostino, Dov M. Gabbay, Sean Matthews and Luca Vigano (Eds.) Kluwer Academic Publishers Page 2. Page 3. Labelled Deduction Thi s One LKC8-ZFQ-6KP6 Page 4. ...

Artificial Intelligence

A well studied instantiation of Dung's abstract theory of argumentation yields argumentationbased... more A well studied instantiation of Dung's abstract theory of argumentation yields argumentationbased characterisations of non-monotonic inference over possibly inconsistent sets of classical formulae. This provides for single-agent reasoning in terms of argument and counter-argument, and distributed non-monotonic reasoning in the form of dialogues between computational and/or human agents. However, features of existing formalisations of classical logic argumentation (Cl-Arg) that ensure satisfaction of rationality postulates, preclude applications of Cl-Arg that account for real-world dialectical uses of arguments by resource-bounded agents. This paper formalises dialectical classical logic argumentation that both satisfies these practical desiderata and is provably rational. In contrast to standard approaches to Cl-Arg we: 1) draw an epistemic distinction between an argument's premises accepted as true, and those assumed true for the sake of argument, so formalising the dialectical move whereby arguments' premises are shown to be inconsistent, and avoiding the foreign commitment problem that arises in dialogical applications; 2) provide an account of Cl-Arg suitable for real-world use by eschewing the need to check that an argument's premises are subset minimal and consistent, and identifying a minimal set of assumptions as to the arguments that must be constructed from a set of formulae in order to ensure that the outcome of evaluation is rational. We then illustrate our approach with a natural deduction proof theory for propositional classical logic that allows measurement of the 'depth' of an argument, such that the construction of depth-bounded arguments is a tractable problem, and each increase in depth naturally equates with an increase in the inferential capabilities of real-world agents. We also provide a resource-bounded argumentative characterisation of non-monotonic inference as defined by Brewka's Preferred Subtheories.

Scientometrics

In many situations we are interested in appraising the value of a certain characteristic for a gi... more In many situations we are interested in appraising the value of a certain characteristic for a given individual relative to the context in which this value is observed. In recent years this problem has become prominent in the evaluation of scientific productivity and impact. A popular approach to such relative valuations consists in using percentile ranks. This is a purely ordinal method that may sometimes lead to counterintuitive appraisals, in that it discards all information about the distance between the raw values within a given context. By contrast, this information is partly preserved by using standardization, i.e., by transforming the absolute values in such a way that, within the same context, the distance between the relative values is monotonically related to the distance between the absolute ones. While there are many practically useful alternatives for standardizing a given characteristic across different contexts, the general problem seems to have never been addressed from a theoretical and normative viewpoint. The main aim of this paper is to fill this gap and provide a conceptual framework that allows for this kind of systematic investigation. We then use this framework to prove that, under some rather weak assumptions, the general format of a standardization function can be determined quite sharply.

Proceedings of the Twenty-Ninth International Joint Conference on Artificial Intelligence

ASPIC+ is an established general framework for argumentation and non-monotonic reasoning. However... more ASPIC+ is an established general framework for argumentation and non-monotonic reasoning. However, ASPIC+ does not satisfy the non-contamination rationality postulates, and moreover, tacitly assumes unbounded resources when demonstrating satisfaction of the consistency postulates. In this paper we present a new version of ASPIC+ – Dialectial ASPIC+ – that is fully rational under resource bounds.

... HANDBOOK OF TABLEAU METHODS Edited by MARCELLO D'AGOSTINO Universita di ... more ... HANDBOOK OF TABLEAU METHODS Edited by MARCELLO D'AGOSTINO Universita di Ferrara, Ferrara, Italy DOV M. GABBAY King's College, London, United ... ISBN 0-7923-5627-6 Published by Kluwer Academic Publishers, PO Box, 3300 AA Dordrecht, The Netherlands. ...

Lecture Notes in Computer Science, 1998

ABSTRACT WinKE is a new interactive theorem proving assistant based on the KE calculus, a refutat... more ABSTRACT WinKE is a new interactive theorem proving assistant based on the KE calculus, a refutation system which combines features from Smullyan’s analytic tableaux and Gentzen’s natural deduction. It has been developed to support teaching logic and reasoning to undergraduate students. The WinKE process of constructing a proof tree is as faithful as possible to the pen-and-paper procedure. Running under Windows 95, it is easy to use and visually satisfying. The WinKE system features an interactive interface via menus, dialogues, and graphic tools, on- and off-line proof-checking, and is completed by the option to automatically perform proofs (or parts of a proof), and to build up countermodels. User support is provided by bookkeeping facilities, hints, various “undo” utilities, and a detailed on-line help system. The system provides several files with example problems. New ones can be edited directly within WinKE. The interface consists of four windows: the main window providing menus and buttons for quick access to the most basic functions, the graphic window to display and manipulate KE proof trees, a viewer which displays a scaled-down view of the virtual drawing board, allowing to focus on a particular portion of it, and a tool box containing the graphic tools. The design of the interface is close to that of Windows standard software, which makes it very easy to learn how to use the system. WinKE is supportive of an introductory textbook on classical logic, but may also be used independently. References and further information about WinKE as well as the KE calculus can be found at the URL: http://dns.unife.it/dgm/WinKE/.

You are, all of you in this community, brothers. But when god fashioned you, he added gold in the... more You are, all of you in this community, brothers. But when god fashioned you, he added gold in the composition of those of you who are qualified to be Rulers (which is why their prestige is greatest); he put silver in the Auxiliaries, and iron and bronze in the farmers and other workers. Now since you are all of the same stock, though your children will commonly resemble their parents, occasionally a silver child will be born of golden parents, or a golden child of silver parents, and so on. Therefore the first and most important of god's commandments to the Rulers is that in the exercise of their function as Guardians their principal care must be to watch the mixture of metals in the characters of their children. If one of their own children has traces of bronze or iron in its make-up, they must harden their hearts, assign it its proper value, and degrade it to the ranks of the industrial and agricoltural class where it properly belongs: similarly, if a child of this class is b...

Journal of Logic, Language and Information, 1992

We show that Smullyan's analytic tableaux cannot p-simulate the truth-tables. We identify the cau... more We show that Smullyan's analytic tableaux cannot p-simulate the truth-tables. We identify the cause of this computational breakdown and relate it to an underlying semantic difficulty which is common to the whole tradition originating in Gentzen's sequent calculus, namely the dissonance between cut-free proofs and the Principle of Bivalence. Finally we discuss some ways in which this principle can be built into a tableau-like method without affecting its "analytic" nature.

Page 1. APPLIED LOGIC SERI Labelled Deduction David Basin, M arcello D&am... more Page 1. APPLIED LOGIC SERI Labelled Deduction David Basin, M arcello D'Agostino, Dov M. Gabbay, Sean Matthews and Luca Vigano (Eds.) Kluwer Academic Publishers Page 2. Page 3. Labelled Deduction Thi s One LKC8-ZFQ-6KP6 Page 4. ...