In this paper, the notion of equivalence models for quantified Boolean formulas with free variables is introduced. The computational complexity of the equivalence model checking problem is investigated in the general case and some restricted cases. We also establish a connection between the structure of some quantified Boolean formulas and the structure of models.

We introduce a first-order language for semantic underspecification that we call Constraint Language for Lambda-Structures (CLLS). A A-structure can be considered as a A-term up to consistent renaming of bound variables (a-equality); a constraint of CLLS is an underspec-ified description of a A-structure. CLLS solves a capturing problem omnipresent in underspec-ified scope representations. CLLS...

If P is a hereditary property then we show that, for the existence of a perfect f -factor, P is a sufficient condition for countable graphs and yields a sufficient condition for graphs of size א1. Further we give two examples of a hereditary property which is even necessary for the existence of a perfect f -factor. We also discuss the א2-case. We consider graphs G = (V,E), where V = V (G) is a ...

Several authors have recently argued that semantic interpretation is subject to economy constraints. In particular, Fox (1999) argued that the interpretation of pronouns is subject to binding economy, which favors local binding over non-local binding. The present paper points out a problem for binding economy. The aim, then, is to see if this problem can be resolved in a conservative way, that ...

We consider the problem of higher-order matching restricted to the set of linear λ-terms (i.e., λ-terms where each abstraction λx.M is such that there is exactly one free occurrence of x in M). We prove that this problem is decidable by showing that it belongs to NP. Then we prove that this problem is in fact NP-complete. Finally, we discuss some heuristics for a practical algorithm.

In this note, we provide an affirmative answer to the title question by giving two examples of cardinals satisfying conditions implying they are non-Rowbottom which can be turned into Rowbottom cardinals via forcing. In our second example, our cardinal is also non-Jonsson. A well-known phenomenon is that under certain circumstances, it is possible to force over a given model V of ZFC containing...

Different theorem provers tend to produce proof objects in different formats and this is especially the case for modal logics, where several deductive formalisms (and provers based on them) have been presented. This work falls within the general project of establishing a common specification language in order to certify proofs given in a wide range of deductive formalisms. In particular, by usi...

Three recent demands on quantifier scoping algorithms have been that they should be explicitly stated, they should be sound and complete with respect to the input sentence [Hobbs and Shieber 1987] and they should not employ a 'Free Variable Constraint' [Pereira 1989]. The first demand is for good academic practice. The second is to ask for an algorithm that generates all and only the possible s...

We describe the construction and use of a system for translating higher order logic-based speciications into programs in the higher order logic programming language Lambda Prolog. The translation improves on previous work in the eld of executing speciications by allowing formulas with quantiiers to be executed, and by permitting users to pose Prolog-style queries with free variables to be insta...

It is often alleged that high auction prices inhibit build-out. We investigate this claim under the extreme case of budget-constrained bidders. Low prices maximize overall the gains from trade. If there are n licenses, the price where the budget constraint just binds maximizes consumer surplus if the elasticity of demand is less than one plus 1/n. If demand is elastic, auctions maximize consume...