136 research outputs found
Constraints on Anaphoric Determiners
10.1007/s11168-011-9076-3Some constraints on functions from sets and relations to sets are studied. Such constraints are satisfied by anaphoric functions, that is functions denoted by anaphoric determiners. These constraints are generalisations of anaphor conditions known from the study of simpler cases of nominal anaphors. In addition a generalisation of the notion of conservativity as applied to anaphoric functions is proposed. Two classes of anaphoric determiners found in NLs are discussed as examples
A semantic constraint on binary determiners
A type quantifier F is symmetric iff F(X, X)(Y ) = F(Y, Y )(X). It is shown that quantifiers denoted by irreducible binary determiners in natural languages are both conservative and symmetric and not only conservative
Lewis meets Brouwer: constructive strict implication
C. I. Lewis invented modern modal logic as a theory of "strict implication".
Over the classical propositional calculus one can as well work with the unary
box connective. Intuitionistically, however, the strict implication has greater
expressive power than the box and allows to make distinctions invisible in the
ordinary syntax. In particular, the logic determined by the most popular
semantics of intuitionistic K becomes a proper extension of the minimal normal
logic of the binary connective. Even an extension of this minimal logic with
the "strength" axiom, classically near-trivial, preserves the distinction
between the binary and the unary setting. In fact, this distinction and the
strong constructive strict implication itself has been also discovered by the
functional programming community in their study of "arrows" as contrasted with
"idioms". Our particular focus is on arithmetical interpretations of the
intuitionistic strict implication in terms of preservativity in extensions of
Heyting's Arithmetic.Comment: Our invited contribution to the collection "L.E.J. Brouwer, 50 years
later
Bootstrapping Inductive and Coinductive Types in HasCASL
We discuss the treatment of initial datatypes and final process types in the
wide-spectrum language HasCASL. In particular, we present specifications that
illustrate how datatypes and process types arise as bootstrapped concepts using
HasCASL's type class mechanism, and we describe constructions of types of
finite and infinite trees that establish the conservativity of datatype and
process type declarations adhering to certain reasonable formats. The latter
amounts to modifying known constructions from HOL to avoid unique choice; in
categorical terminology, this means that we establish that quasitoposes with an
internal natural numbers object support initial algebras and final coalgebras
for a range of polynomial functors, thereby partially generalising
corresponding results from topos theory. Moreover, we present similar
constructions in categories of internal complete partial orders in
quasitoposes
Birational motives, II: Triangulated birational motives
We develop birational versions of Voevodsky's triangulated categories of
motives over a field, and relate them with the pure birational motives studied
in arXiv:0902.4902 [math.AG]. We also get an interpretation of unramified
cohomology in this framework, leading to "higher derived functors of unramified
cohomology".Comment: Compared to the initial version: previous Subsection 4.2 has been
upgraded to Section 5; previous Lemmas 5.2.5 and 5.2.6 have been corrected to
Proposition 6.2.5 and Lemma 6.2.6; at the referee's request, previous
Appendix B and the proof of previous Proposition C.1.1 (now A.4.1) have been
removed (please consult the initial version for them
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