Term-generic logic (TGL) is a first-order logic parameterized with terms defined axiomatically (rather than constructively), by requiring them to only provide generic notions of free variable and substitution satisfying reasonable properties. TGL has a complete Gentzen system generalizing that of first-order logic. A certain fragment of TGL, called Horn, possesses a much simpler Gentzen system,...

Acute pharyngitis is one of the most common illnesses for which children in the United States visit primary care providers; pediatricians make the diagnosis of acute pharyngitis, acute tonsillitis, or “strep throat” more than 7 million times annually. A partial list of the more common microorganisms that can cause acute pharyngitis is presented in Table 27-1. Most cases in children and adolesce...

Thin-shell instability is one process which can generate entangled structures in astrophysical plasma on collisional (fluid) scales. It is driven by a spatially varying imbalance between the ram pressure of the inflowing upstream plasma and the downstream's thermal pressure at a nonplanar shock. Here we show by means of a particle-in-cell simulation that an analog process can destabilize a thin...

The topic of Hamiltonian chaos is a whole course in itself, and we will only touch on a few highlights. For further information see Ott chapter 7, and review papers by Berry [1] and Helleman [2]. The ideal pendulum discussed in chapter 2 is an example of a Hamiltonian system. In many ways this system is typical of the ones taught in elementary courses on mechanics: the orbits are periodic and c...

Background. The contributions of patients’ opinions to the evaluation of health care is widely acknowledged. This study investigates whether the patients of a fundholding practice perceived any changes in the services offered. Aim. To examine the effect of general practice fundholding on patient satisfaction with both primary and secondary care services. Method. In April 1992, questionnaires we...

27.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 311 27.2 Success Stories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313 27.3 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315 Bibl...

Ridge estimate has been suggested as an alternative to the maximum likelihood estimate in the presence of collinearity among the elements of unobservable values in measurement error models. This paper studies the local influence of minor perturbations on the ridge estimate in the measurement error model. The diagnostics under the perturbation of variance and explanatory variables are considered...

The standard first-order reading of modality does not bind individual variables, i.e., if x is free in F (x), then x remains free in 2F (x). Accordingly, if 2 stands for ‘provable in arithmetic,’ ∀x2F (x) states that F (n) is provable for any given value of n = 0, 1, 2, . . .; this corresponds to a de re reading of modality. The other, de dicto meaning of 2F (x), suggesting that F (x) is deriva...

This paper introduces a nested sequent system for predicate logic. The system features a structural universal quantifier and a universally closed existential rule. One nice consequence of this is that proofs of sentences cannot contain free variables. Another nice consequence is that the assumption of a non-empty domain is isolated in a single inference rule. This rule can be removed or added a...

In [3], Keisler proves that if Q1 is a nonstandard model of the complete theory Th(Q) of (Q;+;×; 0; 1) and C1 is the algebraic closure of Q1, then (C1; Q1) is elementarily equivalent to (C;Q) where C is the algebraic closure of Q. But if Q r 1 is the real closure of Q1 and Qr the real closure of Q, then it is observed in [1] that (Q r 1; Q1) ≡(Qr ;Q). Victor Harnik asked the following question:...