On the role of implication in formal logic

2000 ◽  
Vol 65 (3) ◽  
pp. 1076-1114 ◽  
Author(s):  
Jonathan P. Seldin
Keyword(s):  
Higher Order ◽  
Formal Logic ◽  
Combinatory Logic ◽  
Cut Elimination ◽  
Classical Version ◽  
Logical Constants ◽  
Logical Strength ◽  
Special Case

AbstractEvidence is given that implication (and its special case, negation) carry the logical strength of a system of formal logic. This is done by proving normalization and cut elimination for a system based on combinatory logic or λ-calculus with logical constants for and, or, all, and exists, but with none for either implication or negation. The proof is strictly finitary, showing that this system is very weak. The results can be extended to a “classical” version of the system. They can also be extended to a system with a restricted set of rules for implication: the result is a system of intuitionistic higher-order BCK logic with unrestricted comprehension and without restriction on the rules for disjunction elimination and existential elimination. The result does not extend to the classical version of the BCK logic.

scholarly journals Academic policy advice in consensus-seeking countries: the cases of Belgium and Germany

2019 ◽  
pp. 002085231987878 ◽  
Author(s):  
Valérie Pattyn ◽  
Sonja Blum ◽  
Ellen Fobé ◽  
Mirjam Pekar-Milicevic ◽  
Marleen Brans
Keyword(s):  
Academic Research ◽  
Policy Advice ◽  
Current Evidence ◽  
Common Trends ◽  
Policy Advisory Systems ◽  
Academic Policy ◽  
Advisory Systems ◽  
The Government ◽  
Special Case

Research on policy-advisory systems worldwide has shown that historically dominant sources of advice traditionally located in-house to the government have been increasingly supplemented by other actors and outside knowledge. However, the vast majority of research has concentrated on the anglophone context. Yet, countries with a consensus-seeking, neo-corporatist tradition provide a special case in terms of policy advice and merit more scholarly attention. What counts as evidence in these countries is the expert rationality of institutional representatives. The position and role of academic research in consensus-based systems is unclear, and is the focus of this article. Can we observe commonalities across consensus-style countries, or do differences prevail? We investigate two typical consensus-seeking countries: Belgium and Germany. To examine the supply side of policy advice, the article reviews current evidence regarding their policy-advisory systems. For the demand side, we present insights from a survey among federal ministerial officials. We find common trends between the two cases but their nature and extent are idiosyncratic. In Belgium, the supply of and demand for academic policy advice is comparatively lower, while the German case exhibits more change in the advisory landscape and institutionalisation of the supply of and demand for academic research. Points for practitioners   • Countries with a consensus-seeking, neo-corporatist tradition provide a special case in terms of policy advice.   • The findings suggest that there are common trends but their nature and extent are idiosyncratic.   • In Belgium, the supply of and demand for academic advice is comparatively lower.   • Germany’s policy-advisory landscape exhibits more change and institutionalisation of the supply of and demand for academic research.

scholarly journals RATIONAL LOCAL SYSTEMS AND CONNECTED FINITE LOOP SPACES

2021 ◽  
pp. 1-29
Author(s):  
DREW HEARD
Keyword(s):  
Lie Group ◽  
Loop Space ◽  
Algebraic Model ◽  
Compact Lie Group ◽  
Loop Spaces ◽  
Local Systems ◽  
Special Case ◽  
Finite Loop ◽  
Finite Loop Space

Abstract Greenlees has conjectured that the rational stable equivariant homotopy category of a compact Lie group always has an algebraic model. Based on this idea, we show that the category of rational local systems on a connected finite loop space always has a simple algebraic model. When the loop space arises from a connected compact Lie group, this recovers a special case of a result of Pol and Williamson about rational cofree G-spectra. More generally, we show that if K is a closed subgroup of a compact Lie group G such that the Weyl group W G K is connected, then a certain category of rational G-spectra “at K” has an algebraic model. For example, when K is the trivial group, this is just the category of rational cofree G-spectra, and this recovers the aforementioned result. Throughout, we pay careful attention to the role of torsion and complete categories.

scholarly journals Response to governmental COVID-19 restrictions: the role of informal institutions

2021 ◽  
pp. 1-17
Author(s):  
Katarzyna Bentkowska
Keyword(s):  
Social Relations ◽  
Informal Institutions ◽  
Special Case ◽  
Formal Rules

Abstract This paper explains how informal institutions influence the reaction to the COVID-19 pandemic and the response to formal restrictions. I claim that it is not enough to introduce countermeasures, as individuals must follow them if they are to be effective. The acceptance of such measures is reflected in individuals' degrees of mobility decrease and contact reduction, the aims of governmental restrictions. I identify a group of attitudes connected with individuals' responses that differ across countries. They are associated with social relations and approaches to dealing with problems. The analysis confirms that formal restrictions can be seen as successful only if they are supported by strong informal institutions. In some cases, they even define individuals' reactions more than formal recommendations. The findings are useful not only for explaining the special case of reaction to pandemic restrictions but also for investigating what generally determines individuals' compliance with formal rules.

scholarly journals Dynamics of Extreme Stratospheric Negative Heat Flux Events in an Idealized Model

2018 ◽  
Vol 75 (10) ◽  
pp. 3521-3540 ◽  
Author(s):  
Etienne Dunn-Sigouin ◽  
Tiffany Shaw
Keyword(s):  
Heat Flux ◽  
Wave Propagation ◽  
Recent Work ◽  
Wave Interaction ◽  
Higher Order ◽  
Negative Events ◽  
Flow Mechanism ◽  
Mean Flow ◽  
Idealized Model

Recent work has shown that extreme stratospheric wave-1 negative heat flux events couple with the troposphere via an anomalous wave-1 signal. Here, a dry dynamical core model is used to investigate the dynamical mechanisms underlying the events. Ensemble spectral nudging experiments are used to isolate the role of specific dynamical components: 1) the wave-1 precursor, 2) the stratospheric zonal-mean flow, and 3) the higher-order wavenumbers. The negative events are partially reproduced when nudging the wave-1 precursor and the zonal-mean flow whereas they are not reproduced when nudging either separately. Nudging the wave-1 precursor and the higher-order wavenumbers reproduces the events, including the evolution of the stratospheric zonal-mean flow. Mechanism denial experiments, whereby one component is fixed to the climatology and others are nudged to the event evolution, suggest higher-order wavenumbers play a role by modifying the zonal-mean flow and through stratospheric wave–wave interaction. Nudging all tropospheric wave precursors (wave-1 and higher-order wavenumbers) confirms they are the source of the stratospheric waves. Nudging all stratospheric waves reproduces the tropospheric wave-1 signal. Taken together, the experiments suggest the events are consistent with downward wave propagation from the stratosphere to the troposphere and highlight the key role of higher-order wavenumbers.

Higher order neurons in buccal ganglia of Pleurobranchaea elicit vomiting motor activity

1983 ◽  
Vol 50 (3) ◽  
pp. 658-670 ◽  
Author(s):  
A. D. McClellan
Keyword(s):  
High Frequency ◽  
Motor Pattern ◽  
Higher Order ◽  
Root Activity ◽  
Command Neurons ◽  
Sensory Inputs ◽  
Buccal Ganglia ◽  
Output Pattern ◽  
Stimulation Of

The buccal mass of the gastropod Pleurobranchaea is used during a regurgitation response that consists of a writhing phase interrupted by brief periodic bouts of a vomiting phase (17, 20). During transitions from writhing to vomiting, specific changes occur in the motor pattern (19, 20). Evidence is presented suggesting that at least some of the initiation or "command" neurons for vomiting reside in the buccal ganglia. The present paper examines the role of two candidate vomiting-initiation cells, the ventral white cells (VWC) and midganglionic cells (MC), in the buccal ganglia of isolated nervous systems. Stimulation of single VWCs activates a vomiting motor pattern, consisting in part of alternating buccal root activity. Furthermore, the VWCs fire in high-frequency bursts during episodes (i.e., bouts) of this same vomiting pattern. Mutual reexcitation between the VWCs and motor pattern generator (MPG) appears to produce the accelerated buildup and maintenance of vomiting rhythms. Brief stimulation of single MCs "triggers" bouts of a vomiting motor pattern, but the membrane potential of this cell is only modulated during this same pattern, at least in the isolated nervous system. It is proposed that in intact animals the MCs are activated by sensory inputs and briefly excite the VWC-MPG network, thereby turning on the mutual reexcitatory mechanism mentioned above and switching the output pattern. A general implication for gastropod research is that higher order neurons that activate buccal root activity cannot automatically be given the function of "feeding command neuron," as some cells clearly control other responses, such as vomiting.

Sign in / Sign up

Export Citation Format

Share Document