In the last two decades, argumentation has evolved as a powerful
paradigm to formalize commonsense qualitative reasoning. Several
argumentation frameworks have been developed, notably Defeasible
Logic Programming (DeLP) and Possibilistic Defeasible
Logic Programming (P-DeLP), two logic programming approaches
to argumentation which have proven to be successful for many
real-world applications in areas such as multiagent systems,
legal reasoning, and decision support systems, among others.

The notion of accrual of arguments has received some attention
from the argumentation community (e.g. Prakken [3]).
This notion is based on the intuitive idea that having more reasons
or arguments for a given conclusion makes such a conclusion more
credible. Modelling accrual of arguments is not a simple issue,
and it is not formally considered in most existing argumentation
frameworks. Previous research has identified different principles
that should hold for performing accrual of arguments in a sound way.

In this talk we will describe a novel approach to model accrual
of arguments in the context of DeLP. We show that accrued arguments
can be conceptualized as structures which can be subject
to a dialectical analysis similar to the one applied in conventional
argumentation systems. We also analyze Prakken’s
principles in the context of our proposal,
and describe some interesting emerging features.

References:

[1] On the Accrual of Arguments in Defeasible Logic Programming
    (M. Gómez, C. Chesñevar, G. Simari). Proc. of IJCAI 2009, in press.
    July 2009, Pasadena, California, USA.

[2] Modelling Argument Accrual in Possibilistic Defeasible Logic Programming
    (M. Gómez, C. Chesñevar, G. Simari). Proc. of ECSQARU 2009,
    C. Sossai and G. Chemello (Eds.), pp. 131–143, LNAI 5590, 2009.

[3] A study of accrual of arguments, with applications to evidential reasoning
    (H.Prakken). In ICAIL ’05, pages 85–94, 2005.