Preference Logic Research Articles

Logic programming with solution preferences

Preference logic programming (PLP) is an extension of logic programming for declaratively specifying problems requiring optimization or comparison and selection among alternative solutions to a query. PLP essentially separates the programming of a problem itself from the criteria specification of its solution selection. In this paper we present a declarative method for specifying preference logic programs. The method introduces a precise formalization for the syntax and semantics of PLP. The syntax of a preference logic program contains two disjoint sets of definite clauses, separating a core program specifying a general computational problem from its preference rules for optimization; the semantics of PLP is given based on the Herbrand model and fixed point theory, where how preferences affects the least Herbrand model of a logic program is interpreted as a sequence of meta-level mapping operations. In addition, we present an operational semantics based on a new resolution strategy and a memoized recursive algorithm for computing strictly stratified logic programs with well-formed preferences, and further show that the operational semantics of such a preference logic program is consistent to its declarative semantics.

Continuous Preference Logic for System Evaluation

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> In this paper, we investigate mathematical models that are suitable for modeling decisions in the area of system evaluation, comparison, and selection. Our interest is focused on soft computing models that can be directly related to observable properties of human reasoning, and have a record of use in system evaluation practice. We analyze various approaches to defining andness and orness, and use a generalized conjunction/disjunction (GCD) to build compound preference logic functions and logic models for system evaluation. We also present applications of the continuous preference logic in decision models based on the LSP method. </para>

Should the Democrats Move to the Left on Economic Policy?

Could John Kerry have gained votes in the recent Presidential election by more clearly distinguishing himself from George Bush on economic policy? At first thought, the logic of political preferences would suggest not: the Republicans are to the right of most Americans on economic policy, and so in a one-dimensional space with party positions measured with no error, the optimal strategy for the Democrats would be to stand infinitesimally to the left of the Republicans. The median voter theorem suggests that each party should keep its policy positions just barely distinguishable from the opposition. In a multidimensional setting, however, or when voters vary in their perceptions of the parties' positions, a party can benefit from putting some daylight between itself and the other party on an issue where it has a public-opinion advantage (such as economic policy for the Democrats). We set up a plausible theoretical model in which the Democrats could achieve a net gain in votes by moving to the left on economic policy, given the parties' positions on a range of issue dimensions. We then evaluate this model based on survey data on voters' perceptions of their own positions and those of the candidates in 2004. Under our model, it turns out to be optimal for the Democrats to move slightly to the right but staying clearly to the left of the Republicans' current position on economic issues.

Robot navigation in very cluttered environments by preference-based fuzzy behaviors

One of the key challenges in application of Autonomous Ground Vehicles (AGVs) is navigation in environments that are densely cluttered with obstacles. The control task becomes more complex when the configuration of obstacles is not known a priori. The most popular control methods for such systems are based on reactive local navigation schemes that tightly couple the robot actions to the sensor information. Because of the environmental uncertainties, fuzzy behavior systems have been proposed. The most difficult problem in applying fuzzy-reactive-behavior-based navigation control systems is that of arbitrating or fusing the reactions of the individual behaviors, which is addressed here by the use of preference logic. This paper presents the design of a preference-based fuzzy behavior system for navigation control of robotic vehicles using the multivalued logic framework. As shown in simulation and experimental results, the proposed method allows the robot to smoothly and effectively navigate through cluttered environments such as dense forests. Experimental comparisons with the vector field histogram method (VFH) show that the proposed method usually produces smoother albeit longer paths to the goal.

A View From Riggs: Treatment Resistance and Patient Authority—Introduction to Paper IV

As we have noted throughout this evolving series of articles, efforts to approach the problem of treatment resistance generally focus on the development of biological treatment algorithms, with little attention to psychosocial factors or to meaning. The preferred logic of the field is that of evidence–based medicine, with the gold standard of evidence the randomized controlled trial. This series of articles has introduced alternative points of view to the conceptualization and understanding of the treatment resistant or treatment refractory patient drawn from our experience at Riggs. My first article in the series (Plakun, 2006) surveyed the scope of treatment resistant patients and defined a subgroup who benefit from an alternate approach, and then emphasized the importance of attending to and utilizing negative transference and countertransference in work with such patients. The second article by Jerry Fromm (2006) focused on the way trauma from a previous generation may lead to what appears to be treatment resistance in a patient. In the third series article, David Mintz and Barri Belnap introduced “psychodynamic psychopharmacology” to the field, noting the importance of including careful attention to the meaning of medication along with knowledge of pharmacological effects, particularly in work with treatment resistant patients. Now, in the fourth series article, John Muller offers a conceptual article explicating and further developing the notion of the “Third” in psychoanalytic treatment, and explains how this notion plays a role in treatment resistance. Muller introduces us to the notion of the Third and its origin, and then differentiates the developmental, relational, and structural thirds as a way of clarifying what has sometimes seemed a hard to define and shifting concept. Among other points he makes is to show how representative clinical interventions from the earlier series articles by Fromm and by me may be understood as clinical applications of his notion of the Third. Muller’s elucidation of the Third helps illuminate often invisible

Dynamic logic of preference upgrade

Statements not only update our current knowledge, but also have other dynamic effects. In particular, suggestions or commands ‘upgrade' our preferences by changing the current order among worlds. We present a complete logic of knowledge update plus preference upgrade that works with dynamic-epistemic-style reduction axioms. This system can model changing obligations, conflicting commands, or ‘regret'. We then show how to derive reduction axioms from arbitrary definable relation changes. This style of analysis also has a product update version with preferences between actions, as well as worlds. Some illustrations are presented involving defaults and obligations. We conclude that our dynamic framework is viable, while admitting a further extension to more numerical ‘utility update'.

A Preference Logic Based on Various Kinds of Preferences

Presently,a whole logic system is still absent to represent and reason various kinds of preferences.In this paper,a preference logic MPL(logic of many kinds of preference)is introduced to supply the gap.In addition, recurring to the minimal/maximal specificity principle,a non-monotonic semantics of MPL's language L_(MPL)is defined,and the application and capability of MPL are initially investigated by rewriting preferences expressed by ranked knowledge based into L_(MPL).Moreover,the conclusion and the prospective are presented in the end.

The influence of the “organisation” on the logics of action‐pervading disciplinary decision making

PurposeThis paper aims to advance understanding of the disciplinary decision‐making process underpinning the professional ethics machinery employed by professional accounting organisations, using elements of francophone organisational analysis to examine the influence of the key formal organisational components established by the Institute of Chartered Accountants in Ireland (ICAI) to administer its disciplinary decision‐making process up to December 1999.Design/methodology/approachThe paper uses evidence gathered from a series of in‐depth interviews with members of the ICAI disciplinary and investigation committees.FindingsIlluminates the internal tensions and conflicts permeating the disciplinary decision‐making process of the ICAI and the influence key organisational components have on resolving these conflicts through their encouragement of decision making driven by a preferred reasoning or logic of action.Research limitations/implicationsThe evidence presented questions the public interest proclamations of the ICAI with respect to its disciplinary procedures pre‐December 1999. It further exposes the tensions between profession protection and society protection motives in the disciplinary decision making of accounting bodies.Originality/valueThis paper represents a first attempt at getting inside the disciplinary decision‐making process of a professional accounting body to examine the process using the voices of process participants.

Process in Reality: A logical offering

The conjunction of process and reality is familiar from the original theory of A. N. Whitehead and the subsequent development of process philosophy and metaphysics by Nicholas Rescher. Classical logic, however, is either ignored or stated to be inappropriate to a discussion of process. In this paper, I will show that the value of a process view of reality can be enhanced by reference to a new, transconsistent logic of reality that is grounded in the physical properties of energy in its various forms. These properties justify a principle of dynamic antagonism or opposition that explicates the phenomena of change at all levels of reality. It can be, accordingly, a preferred logic for understanding the dynamics of real processes.

Entrepreneurial logics for a technology of foolishness

Several years ago Professor March pointed out that rational choice involves two guesses, a guess about uncertain future consequences and a guess about uncertain future preferences, and called for the development of a technology of foolishness to complement the technologies of intelligence that have been developed to improve the first guess. In this essay we use empirical data from two separate studies of entrepreneurial expertise, one involving the creation of new ventures and the other the birth of a new industry to identify three logics that constitute working elements of a technology of foolishness: (1) the logic of identity, as opposed to the logic of preferences; (2) the logic of action, as opposed to the logic of belief; and (3) the logic of commitment, as opposed to the logic of transaction.

Logika preferencija na grubim i rasplinutim skupovima

Theories of fuzzy sets and rough sets, as alternatives to the usual set theory founded on the two valued classical logic, present an appropriate context for developing the basic notions of the logic of preference and consequently, of the social choice theory. In this paper we present an introductory survey of two non-classical concepts of set: fuzzy set and rough set, as originally introduced by L. A. Zadeh and Z. Pawlak respectively, and then we prove that a preference relation defined by means of rough sets has the same basic properties as the classical or the fuzzy one. Moreover, we prove that The Liberal Paradox, as originally formulated by A. Sen, holds in the framework of theory of rough sets as well.

From Classical to Intuitionistic Probability

We generalize the Kolmogorov axioms for probability calculus to obtain conditions defining, for any given logic, a class of probability functions relative to that logic, coinciding with the standard probability functions in the special case of classical logic but allowing consideration of other classes of "essentially Kolmogorovian" probability functions relative to other logics. We take a broad view of the Bayesian approach as dictating inter alia that from the perspective of a given logic, rational degrees of belief are those representable by probability functions from the class appropriate to that logic. Classical Bayesianism, which fixes the logic as classical logic, is only one version of this general approach. Another, which we call Intuitionistic Bayesianism, selects intuitionistic logic as the preferred logic and the associated class of probability functions as the right class of candidate representions of epistemic states (rational allocations of degrees of belief). Various objections to classical Bayesianism are, we argue, best met by passing to intuitionistic Bayesianism—in which the probability functions are taken relative to intuitionistic logic—rather than by adopting a radically non-Kolmogorovian, for example, nonadditive, conception of (or substitute for) probability functions, in spite of the popularity of the latter response among those who have raised these objections. The interest of intuitionistic Bayesianism is further enhanced by the availability of a Dutch Book argument justifying the selection of intuitionistic probability functions as guides to rational betting behavior when due consideration is paid to the fact that bets are settled only when/if the outcome bet on becomes known.

Reasoning with different levels of uncertainty

We introduce a family of preferential logics that are useful for handling information with different levels of uncertainty. The corresponding consequence relations are nonmonotonic, paraconsistent, adaptive, and rational. It is also shown that the formalisms in this family can be embedded in corresponding four-valued logics with at most three uncertainty levels, and that reasoning with these logics can be simulated by algorithms for processing circumscriptive theories, such as DLS and SCAN.

The Language of Practical Philosophy

Kant’s criticism is based on the idea that all possible knowledge of facts is determined by the immanent structure of our apparatus of cognition, and that therefore we have no access to reality as it is per se (“Ding an sich”). In modern analytical philosophy some elements of this view survived, namely, the distinction between framework construction and actual data of experience, supposition or voluntary setting. The conditio humana is characterised by our capacity of acting. Acting is defined as behaviour determined and controlled by information processes. The structure of these processes defines the semantics and logical principles of practical philosophy. From this view follows the conception of value judgments, the logic of preferences, formal teleology, the analysis of utility and norm logic. The framework theories should be open in order to be able to express all possible theoretical views, namely, subjectivism as well as objectivism. The paper gives a concise account of the systems of practical thought (formal axiology, formal teleology, preference logic and norm logic) and their gnoseological problems.

Preference Logic Grammars: Fixed point semantics and application to data standardization

The addition of preferences to normal logic programs is a convenient way to represent many aspects of default reasoning. If the derivation of an atom A 1 is preferred to that of an atom A 2, a preference rule can be defined so that A 2 is derived only if A 1 is not. Although such situations can be modelled directly using default negation, it is often easier to define preference rules than it is to add negation to the bodies of rules. As first noted by Govindarajan et al. [Proc. Internat. Conf. on Logic Programming, 1995, pp. 731–746], for certain grammars, it may be easier to disambiguate parses using preferences than by enforcing disambiguation in the grammar rules themselves. In this paper we define a general fixed-point semantics for preference logic programs based on an embedding into the well-founded semantics, and discuss its features and relation to previous preference logic semantics. We then study how preference logic grammars are used in data standardization, the commercially important process of extracting useful information from poorly structured textual data. This process includes correcting misspellings and truncations that occur in data, extraction of relevant information via parsing, and correcting inconsistencies in the extracted information. The declarativity of Prolog offers natural advantages for data standardization, and a commercial standardizer has been implemented using Prolog. However, we show that the use of preference logic grammars allow construction of a much more powerful and declarative commercial standardizer, and discuss in detail how the use of the non-monotonic construct of preferences leads to improved commercial software.

Preference queries in deductive databases

Traditional database query languages such as datalog and SQL allow the user to specify only mandatory requirements on the data to be retrieved from a database. In many applications, it may be natural to express not only mandatory requirements but also preferences on the data to be retrieved. Lacroix and Lavency10) extended SQL with a notion of preference and showed how the resulting query language could still be translated into the domain relational calculus. We explore the use of preference in databases in the setting of datalog. We introduce the formalism of preference datalog programs (PDPs) as preference logic programs without uninterpreted function symbols for this purpose. PDPs extend datalog not only with constructs to specify which predicate is to be optimized and the criterion for optimization but also with constructs to specify which predicate to be relaxed and the criterion to be used for relaxation. We can show that all of the soft requirements in Reference10) can be directly encoded in PDP. We first develop anaively-pruned bottom-up evaluation procedure that is sound and complete for computing answers to normal and relaxation queries when the PDPs are stratified, we then show how the evaluation scheme can be extended to the case when the programs are not necessarily stratified, and finally we develop an extension of themagic templates method for datalog14) that constructs an equivalent but more efficient program for bottom-up evaluation.

A Logical Analysis of the Relationship between Commitment and Obligation

In this paper, we analyze the relationship between commitment and obligation from a logical viewpoint. The principle of commitment implying obligation is proven in a specific logic of action preference which is a generalization of Meyer's dynamic deontic logic. In the proposed formalism, an agent's commitment to goals is considered as a special kind of action which can change one's deontic preference and one's obligation to take some action is based on the preference and the effects of the action. In this logic, it is shown that an agent has the obligation to take any action which is necessary for achieving as many committed goals as possible. The semantics of our logic is based on the possible world models for the dynamic logic of actions. A binary preference relation between possible worlds is associated with the model. Then the preference between actions are determined by comparing that of their consequences. According to the semantics, while the preference will influence the agent's choice of action, commitment is a kind of action that will change the agent's preference. Thus we can show how obligations arise from commitments via updating of deontic preference. The integrated semantics make it possible to express and reason about the mutual relationship among these mental attitudes in a common logic.

Making science relevant to environmental policy

Abstract Implementation of current environmental and natural resource policy has created an era of regulatory discontent, and has prompted calls for new approaches to management that can achieve both long-term ecological sustainability and improved policy performance. These new approaches, such as ecosystem management, emphasize the importance of holistic and integrated science, meaningful public involvement to reflect changing societal goals and objectives, collaborative decisionmaking, and flexible and adaptable institutions. Implementing such approaches will require significant institutional change in all institutions, including the institution of science. Attributes of the scientific culture — including adherence to the myth of objective, value-free science, preference for technical solutions as first-order solutions, and advancement of the scientific method and scientific rationality as preferred logic — have often worked to separate scientists from citizens and science from the policymaking process. They have also fostered undemocratic processes and results. Changes in the institution and culture of science, including embracing more holistic and integrated scientific processes, creating a more civic science, and rethinking the role of scientific advocacy in the policy process, will be required to move toward democratic as well as ecological sustainability.

Distance based revision of preferential logics

We first analyze AGM revision as conditions on choice functions for sets of models. This abstraction seems to us to capture the essentials of classical revision, it also immediately reveals the connection between revision and ranked preferential models, and gives further insight into the distance semantics for revision as developed by Lehmann, Magidor, and Schlechta. Our analysis shows how to apply the essential ideas of revision to other situations than classical theories and formulas, we exemplify this by examining preferential databases. We revise one preferential logic or database, |∼ with another one, |∼'. The basic idea is to describe such a logic as a partial order, either as the order of a preferential model which defines the logic, or as the order between formulas defined by the logic. A partial order can be seen as the set of total orders which extend it, and, given a distance on the set of total orders, we can define a revision as follows: |∼* |∼' will be the logic corresponding to the partial order generated by those total orders extending (the order of) |∼', which are closest to the set of total orders extending (the order of) |∼. We thus give a semantical approach to the problem. A representation result is proven.

On the possibility theory-based semantics for logics of preference

In this paper, we study the semantics for the logics of preference based on possibility theory. Possibility distributions representing the preference between worlds are associated with the possible world models for dynamic logics. Then the preference between actions are determined by comparing some measures of their consequences. We define different logics of preference by considering the comparisons of possibility measures and guaranteed possibility measures. Some properties of the proposed logics are studied and their relationships with deontic logics are also considered.