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Potentially subject to defeat, termination, or Annulment upon the occurrence of a future action or event, or the performance of a condition subsequent.The most common legal application of the term is with respect to estates as interest in land, such as in the case of a conveyance or a life estate, which is defeasible upon the happening of a certain specified event, for example, the death of the person holding such an interest.


adjective confutable, dismissible, dissoluble, functus officio, refutable, revocable, subject to being abrogated, subject to being annulled, subject to being cancelled, subject to being divested, subject to being invalidated, subject to being repealed, subject to being retracted, subject to being revoked, subject to being taken away, subject to being withdrawn, terminable, voidable
Associated concepts: defeasible deed, defeasible estate, deeeasible fee, defeasible interest, defeasible remainder, deeeasible title, determinable fee



DEFEASIBLE. What may be undone or annulled.

References in periodicals archive ?
Defeasible reasoning (see section 3) is useful in various applications, like brokering [21], bargaining and agent negotiations [22].
Figure 8: Results of defeasible reasoning exported as an RDF document.
While the three reasoners featured in [26] are all based on declarative rule languages, EMERALD proposes a variety of reasoning services, including deductive, defeasible and modal defeasible reasoning, thus, comprising a more integrated solution.
Thesis [Simari 1989; Simari and Loui 1992] presents a system for defeasible reasoning in which a general theory of warrant (following Pollock [1987]) and the definition of specificity (as proposed by Poole [1988]) are combined.
Gustavo Bodanza [Bodanza and Simari 1995] analyzed defeasible reasoning in disjunctive databases.
Most of John Pollock's work on defeasible reasoning in the last two decades has been devoted to investigating the processes to be performed by an intelligent agent so that his or her conclusions and decisions can be considered as rational.
Ronald Loui [1991a; 1993b] explicitly investigated the appropriateness of formal dialectics as a basis for nonmonotonic reasoning and defeasible reasoning that takes computational limits seriously.
Robert Kowalski and Francesca Toni [1996] have outlined a formal theory of argumentation, in which they argue that defeasible reasoning with rules of the form P if Q can be understood as "exact" reasoning with rules of the form P if Q and S cannot be shown, where S stands for one or more defeasible "nonprovability claims.
Gordon [1987] developed OBLOG-2, a hybrid knowledge representation system for defeasible reasoning.
Loui [1989b] outlined a formalism for handling defeasible reasoning about decision.
This new model incorporates some concepts of his theory of defeasible reasoning [Pollock 1974; 1995].
Pollock goes on in the body of the book to describe an architecture which would implement his preferred mode of defeasible reasoning but by then he has left behind the normative questions just raised.