32,067 research outputs found
A logic with temporally accessible iteration
Deficiency in expressive power of the first-order logic has led to developing
its numerous extensions by fixed point operators, such as Least Fixed-Point
(LFP), inflationary fixed-point (IFP), partial fixed-point (PFP), etc. These
logics have been extensively studied in finite model theory, database theory,
descriptive complexity. In this paper we introduce unifying framework, the
logic with iteration operator, in which iteration steps may be accessed by
temporal logic formulae. We show that proposed logic FO+TAI subsumes all
mentioned fixed point extensions as well as many other fixed point logics as
natural fragments. On the other hand we show that over finite structures FO+TAI
is no more expressive than FO+PFP. Further we show that adding the same
machinery to the logic of monotone inductions (FO+LFP) does not increase its
expressive power either
Constructing meaning in the service of power : an analysis of the typical modes of ideology in accounting textbooks
This paper provides an analysis of the typical modes of ideology in introductory financial accounting textbooks and training materials. Drawing on Thompson's (1990) schema concerning the typical linguistic modes through which ideology operates, this research suggests that the operation of ideology is apparent within educational accounting texts, with particular strategies being more evident than others: in particular, the strategies of universalization, narrativization, rationalization and naturalization. Given the predominantly technical nature of introductory financial accounting textbooks and training manuals, the modes of ideology identified in the texts were often quite subtle; more specifically, the ideological characteristics displayed in each of the six texts analysed were often expressions of implicit or taken-for-granted assumptions
Cumulants and convolutions via Abel polynomials
We provide an unifying polynomial expression giving moments in terms of
cumulants, and viceversa, holding in the classical, boolean and free setting.
This is done by using a symbolic treatment of Abel polynomials. As a
by-product, we show that in the free cumulant theory the volume polynomial of
Pitman and Stanley plays the role of the complete Bell exponential polynomial
in the classical theory. Moreover via generalized Abel polynomials we construct
a new class of cumulants, including the classical, boolean and free ones, and
the convolutions linearized by them. Finally, via an umbral Fourier transform,
we state a explicit connection between boolean and free convolution
An Extended action for the effective field theory of dark energy: a stability analysis and a complete guide to the mapping at the basis of EFTCAMB
We present a generalization of the effective field theory (EFT) formalism for
dark energy and modified gravity models to include operators with higher order
spatial derivatives. This allows the extension of the EFT framework to a wider
class of gravity theories such as Horava gravity. We present the corresponding
extended action, both in the EFT and the Arnowitt-Deser-Misner (ADM) formalism,
and proceed to work out a convenient mapping between the two, providing a self
contained and general procedure to translate a given model of gravity into the
EFT language at the basis of the Einstein-Boltzmann solver EFTCAMB. Putting
this mapping at work, we illustrate, for several interesting models of dark
energy and modified gravity, how to express them in the ADM notation and then
map them into the EFT formalism. We also provide for the first time, the full
mapping of GLPV models into the EFT framework. We next perform a thorough
analysis of the physical stability of the generalized EFT action, in absence of
matter components. We work out viability conditions that correspond to the
absence of ghosts and modes that propagate with a negative speed of sound in
the scalar and tensor sector, as well as the absence of tachyonic modes in the
scalar sector. Finally, we extend and generalize the phenomenological basis in
terms of -functions introduced to parametrize Horndeski models, to
cover all theories with higher order spatial derivatives included in our
extended action. We elaborate on the impact of the additional functions on
physical quantities, such as the kinetic term and the speeds of propagation for
scalar and tensor modes.Comment: 36 pages, matches published version, typos correcte
Unifying synchronous tree-adjoining grammars and tree transducers via bimorphisms.
We place synchronous tree-adjoining grammars and tree transducers in the single overarching framework of bimorphisms, continuing the unification of synchronous grammars and tree transducers initiated by Shieber (2004). Along the way, we present a new definition of the tree-adjoining grammar derivation relation based on a novel direct inter-reduction of TAG and monadic macro tree transducers.Engineering and Applied Science
Expressing the Behavior of Three Very Different Concurrent Systems by Using Natural Extensions of Separation Logic
Separation Logic is a non-classical logic used to verify pointer-intensive
code. In this paper, however, we show that Separation Logic, along with its
natural extensions, can also be used as a specification language for
concurrent-system design. To do so, we express the behavior of three very
different concurrent systems: a Subway, a Stopwatch, and a 2x2 Switch. The
Subway is originally implemented in LUSTRE, the Stopwatch in Esterel, and the
2x2 Switch in Bluespec
Uniform Strategies
We consider turn-based game arenas for which we investigate uniformity
properties of strategies. These properties involve bundles of plays, that arise
from some semantical motive. Typically, we can represent constraints on allowed
strategies, such as being observation-based. We propose a formal language to
specify uniformity properties and demonstrate its relevance by rephrasing
various known problems from the literature. Note that the ability to correlate
different plays cannot be achieved by any branching-time logic if not equipped
with an additional modality, so-called R in this contribution. We also study an
automated procedure to synthesize strategies subject to a uniformity property,
which strictly extends existing results based on, say standard temporal logics.
We exhibit a generic solution for the synthesis problem provided the bundles of
plays rely on any binary relation definable by a finite state transducer. This
solution yields a non-elementary procedure.Comment: (2012
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