TY - GEN

T1 - An argumentation theoretic semantics based on non-refutable falsity

AU - Júlio Alferes, José

AU - Moniz Pereira, Luís

N1 - Publisher Copyright:
© Springer-Verlag Berlin Heidelberg 1995.

PY - 1995

Y1 - 1995

N2 - We contend that the well-founded semantics (WFS), for normal program, and similarly the well-founded semantics with explicit negation (WFSX), for extended ones are, by design, overly careful in deciding about the falsity of some atoms, by leaving them undefined. We’ve dealt with this issue in normal programs and have previously defined the O-semantics, one that extends WFS by addjoining to it more negative assumptions, at the expense of undefined literals. The goal of this paper is to generalize that work to extended programs, and define a semantics for such programs that enlarges WFSX with more negative assumptions. To achieve this we view default literals as arguments a rational agent can sustain along with the program. As our goal is to enlarge WFSX, we consider the latter as the common reasoning ground and argumentation tool of agents. With this basis, and in order to define the semantics, we first formalize the concepts of consistent and non-refutable sets of arguments (or of hypotheses). In general several such sets may exist. So, and in order to define a unique semantics, given by a single set of additional assumptions, we introduce an additional non-refutability of arguments criterium - tenability - for always and finally preferring just one set of arguments over another.

AB - We contend that the well-founded semantics (WFS), for normal program, and similarly the well-founded semantics with explicit negation (WFSX), for extended ones are, by design, overly careful in deciding about the falsity of some atoms, by leaving them undefined. We’ve dealt with this issue in normal programs and have previously defined the O-semantics, one that extends WFS by addjoining to it more negative assumptions, at the expense of undefined literals. The goal of this paper is to generalize that work to extended programs, and define a semantics for such programs that enlarges WFSX with more negative assumptions. To achieve this we view default literals as arguments a rational agent can sustain along with the program. As our goal is to enlarge WFSX, we consider the latter as the common reasoning ground and argumentation tool of agents. With this basis, and in order to define the semantics, we first formalize the concepts of consistent and non-refutable sets of arguments (or of hypotheses). In general several such sets may exist. So, and in order to define a unique semantics, given by a single set of additional assumptions, we introduce an additional non-refutability of arguments criterium - tenability - for always and finally preferring just one set of arguments over another.

UR - http://www.scopus.com/inward/record.url?scp=84959348459&partnerID=8YFLogxK

U2 - 10.1007/BFb0030657

DO - 10.1007/BFb0030657

M3 - Conference contribution

AN - SCOPUS:84959348459

SN - 3540594671

SN - 978-3-540-59467-3

T3 - Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)

SP - 3

EP - 22

BT - Non-Monotonic Extensions of Logic Programming - ICLP 1994 Workshop, Selected Papers

A2 - Dix, Jürgen

A2 - Przymusinski, Teodor C.

A2 - Pereira, Louis Moniz

PB - Springer

CY - Berlin, Heidelberg

T2 - Workshop on Non-Monotonic Extensions of Logic Programming, ICLP 1994

Y2 - 17 June 1994 through 17 June 1994

ER -