3,214 research outputs found
Are there Hilbert-style Pure Type Systems?
For many a natural deduction style logic there is a Hilbert-style logic that
is equivalent to it in that it has the same theorems (i.e. valid judgements
with empty contexts). For intuitionistic logic, the axioms of the equivalent
Hilbert-style logic can be propositions which are also known as the types of
the combinators I, K and S. Hilbert-style versions of illative combinatory
logic have formulations with axioms that are actual type statements for I, K
and S. As pure type systems (PTSs)are, in a sense, equivalent to systems of
illative combinatory logic, it might be thought that Hilbert-style PTSs (HPTSs)
could be based in a similar way. This paper shows that some PTSs have very
trivial equivalent HPTSs, with only the axioms as theorems and that for many
PTSs no equivalent HPTS can exist. Most commonly used PTSs belong to these two
classes. For some PTSs however, including lambda* and the PTS at the basis of
the proof assistant Coq, there is a nontrivial equivalent HPTS, with axioms
that are type statements for I, K and S.Comment: Accepted in Logical Methods in Computer Scienc
Geïntegreerde akkerbouw: vooral lagere milieubelasting
In samenspraak met een klankbordgroep van akkerbouwers in het noordelijk kleigebied berekende PPO voor verschillende bedrijfstypen (graan; pootaardappelen; consumptieaardappelen) de bedrijfseconomische en milieutechnische resultaten van een geïntegreerde bedrijfsvoering in vergelijking met de gangbare bedrijfsvoering. De verschillen betreffen vooral bemesting, gewasbescherming, arbeidsbehoefte en gewasopbrengsten. In tabellen de kosten en opbrengsten, de mineralenbalansen (overschotten voor N, P2O5 en K2O), en de milieuscores (milieubelastingpunten, MBP; blootstellingsrisicoindex, BRI; inzet van actieve stof
Sodium-glucose cotransporter 2 inhibitors:extending the indication to non-diabetic kidney disease?
This year the medical community was pleasantly surprised by the results of the first large outcome trial that primarily examined the renal effects of the sodium-glucose cotransporter 2 (SGLT2) inhibitor canagliflozin (CANA) in subjects with diabetes and impaired kidney function. The Evaluation of the Effects of Canagliflozin on Renal and Cardiovascular Outcomes in Participants With Diabetic Nephropathy (CREDENCE) trial showed that CANA, relative to placebo, reduces the risk for end-stage renal disease, doubling of creatinine or renal death by 34% [hazard ratio 0.66 (95% confidence interval 0.53-0.81]. These effects were consistent across baseline estimated glomerular filtration rate (eGFR) and haemoglobin A1c subgroups. In this review we combine the results of the CREDENCE trial with those of several cardiovascular outcome trials with SGLT2 inhibitors and show that, unexpectedly, patients with lower eGFR levels may have greater benefit with respect to cardiovascular outcome than patients with normal kidney function. The cardio- and renoprotective effects of SGLT2 inhibitors seem to be independent of their glucose-lowering effects, as shown in several post hoc analyses. In this review we discuss the alleged mechanisms of action that explain the beneficial effects of this novel class of drugs. Moreover, we discuss whether these findings indicate that this class of drugs may also be beneficial in non-diabetic chronic kidney diseases
Admixtures to d-wave gap symmetry in untwinned YBa2Cu3O7 superconducting films measured by angle-resolved electron tunneling
We report on an \textit{ab}-anisotropy of and in
ramp-edge junctions between untwinned YBaCuO and % -wave
Nb. For these junctions, the angle with the YBaCuO
crystal b-axis is varied as a single parameter. The
A()-dependence presents 2-fold symmetry. The minima in
at suggest a real s-wave subdominant
component and negligible -wave or imaginary s-wave admixtures. The
()-dependence is well-fitted by 83% -, 15%
isotropic - and 2% anisotropic s-wave order parameter symmetry, consistent
with .Comment: 4 pages, 3 figures, to be published in Physical Review Letter
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