50,308 research outputs found
Model-Checking Process Equivalences
Process equivalences are formal methods that relate programs and system
which, informally, behave in the same way. Since there is no unique notion of
what it means for two dynamic systems to display the same behaviour there are a
multitude of formal process equivalences, ranging from bisimulation to trace
equivalence, categorised in the linear-time branching-time spectrum.
We present a logical framework based on an expressive modal fixpoint logic
which is capable of defining many process equivalence relations: for each such
equivalence there is a fixed formula which is satisfied by a pair of processes
if and only if they are equivalent with respect to this relation. We explain
how to do model checking, even symbolically, for a significant fragment of this
logic that captures many process equivalences. This allows model checking
technology to be used for process equivalence checking. We show how partial
evaluation can be used to obtain decision procedures for process equivalences
from the generic model checking scheme.Comment: In Proceedings GandALF 2012, arXiv:1210.202
Linear Logic for Meaning Assembly
Semantic theories of natural language associate meanings with utterances by
providing meanings for lexical items and rules for determining the meaning of
larger units given the meanings of their parts. Meanings are often assumed to
combine via function application, which works well when constituent structure
trees are used to guide semantic composition. However, we believe that the
functional structure of Lexical-Functional Grammar is best used to provide the
syntactic information necessary for constraining derivations of meaning in a
cross-linguistically uniform format. It has been difficult, however, to
reconcile this approach with the combination of meanings by function
application. In contrast to compositional approaches, we present a deductive
approach to assembling meanings, based on reasoning with constraints, which
meshes well with the unordered nature of information in the functional
structure. Our use of linear logic as a `glue' for assembling meanings allows
for a coherent treatment of the LFG requirements of completeness and coherence
as well as of modification and quantification.Comment: 19 pages, uses lingmacros.sty, fullname.sty, tree-dvips.sty,
latexsym.sty, requires the new version of Late
Argument Mining with Structured SVMs and RNNs
We propose a novel factor graph model for argument mining, designed for
settings in which the argumentative relations in a document do not necessarily
form a tree structure. (This is the case in over 20% of the web comments
dataset we release.) Our model jointly learns elementary unit type
classification and argumentative relation prediction. Moreover, our model
supports SVM and RNN parametrizations, can enforce structure constraints (e.g.,
transitivity), and can express dependencies between adjacent relations and
propositions. Our approaches outperform unstructured baselines in both web
comments and argumentative essay datasets.Comment: Accepted for publication at ACL 2017. 11 pages, 5 figures. Code at
https://github.com/vene/marseille and data at http://joonsuk.org
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