78,812 research outputs found
From Linear to Branching-Time Temporal Logics: Transfer of Semantics and Definability
This paper investigates logical aspects of combining linear orders as semantics for modal and temporal logics, with modalities for possible paths, resulting in a variety of branching time logics over classes of trees. Here we adopt a unified approach to the Priorean, Peircean and Ockhamist semantics for branching time logics, by considering them all as fragments of the latter, obtained as combinations, in various degrees, of languages and semantics for linear time with a modality for possible paths. We then consider a hierarchy of natural classes of trees and bundled trees arising from a given class of linear orders and show that in general they provide different semantics. We also discuss transfer of definability from linear orders to trees and introduce a uniform translation from Priorean to Peircean formulae which transfers definability of properties of linear orders to definability of properties of all paths in tree
A Finite Semantics of Simply-Typed Lambda Terms for Infinite Runs of<br> Automata
Model checking properties are often described by means of finite automata.
Any particular such automaton divides the set of infinite trees into finitely
many classes, according to which state has an infinite run. Building the full
type hierarchy upon this interpretation of the base type gives a finite
semantics for simply-typed lambda-trees.
A calculus based on this semantics is proven sound and complete. In
particular, for regular infinite lambda-trees it is decidable whether a given
automaton has a run or not. As regular lambda-trees are precisely recursion
schemes, this decidability result holds for arbitrary recursion schemes of
arbitrary level, without any syntactical restriction.Comment: 23 page
Anchoring a Lexicalized Tree-Adjoining Grammar for Discourse
We here explore a ``fully'' lexicalized Tree-Adjoining Grammar for discourse
that takes the basic elements of a (monologic) discourse to be not simply
clauses, but larger structures that are anchored on variously realized
discourse cues. This link with intra-sentential grammar suggests an account for
different patterns of discourse cues, while the different structures and
operations suggest three separate sources for elements of discourse meaning:
(1) a compositional semantics tied to the basic trees and operations; (2) a
presuppositional semantics carried by cue phrases that freely adjoin to trees;
and (3) general inference, that draws additional, defeasible conclusions that
flesh out what is conveyed compositionally.Comment: 7 pages, uses aclcol.st
A Corpus-based Toy Model for DisCoCat
The categorical compositional distributional (DisCoCat) model of meaning
rigorously connects distributional semantics and pregroup grammars, and has
found a variety of applications in computational linguistics. From a more
abstract standpoint, the DisCoCat paradigm predicates the construction of a
mapping from syntax to categorical semantics. In this work we present a
concrete construction of one such mapping, from a toy model of syntax for
corpora annotated with constituent structure trees, to categorical semantics
taking place in a category of free R-semimodules over an involutive commutative
semiring R.Comment: In Proceedings SLPCS 2016, arXiv:1608.0101
A Parameterised Hierarchy of Argumentation Semantics for Extended Logic Programming and its Application to the Well-founded Semantics
Argumentation has proved a useful tool in defining formal semantics for
assumption-based reasoning by viewing a proof as a process in which proponents
and opponents attack each others arguments by undercuts (attack to an
argument's premise) and rebuts (attack to an argument's conclusion). In this
paper, we formulate a variety of notions of attack for extended logic programs
from combinations of undercuts and rebuts and define a general hierarchy of
argumentation semantics parameterised by the notions of attack chosen by
proponent and opponent. We prove the equivalence and subset relationships
between the semantics and examine some essential properties concerning
consistency and the coherence principle, which relates default negation and
explicit negation. Most significantly, we place existing semantics put forward
in the literature in our hierarchy and identify a particular argumentation
semantics for which we prove equivalence to the paraconsistent well-founded
semantics with explicit negation, WFSX. Finally, we present a general proof
theory, based on dialogue trees, and show that it is sound and complete with
respect to the argumentation semantics.Comment: To appear in Theory and Practice of Logic Programmin
Factoring Predicate Argument and Scope Semantics : underspecified Semantics with LTAG
In this paper we propose a compositional semantics for lexicalized tree-adjoining grammar (LTAG). Tree-local multicomponent derivations allow separation of the semantic contribution of a lexical item into one component contributing to the predicate argument structure and a second component contributing to scope semantics. Based on this idea a syntax-semantics interface is presented where the compositional semantics depends only on the derivation structure. It is shown that the derivation structure (and indirectly the locality of derivations) allows an appropriate amount of underspecification. This is illustrated by investigating underspecified representations for quantifier scope ambiguities and related phenomena such as adjunct scope and island constraints
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