11 research outputs found
Minimal Negation in the Ternary Relational Semantics
Minimal Negation is defined within the basic positive relevance logic in the relational ternary semantics: B+. Thus, by defining a number of subminimal negations in the B+ context, principles of weak negation are shown to be isolable. Complete ternary semantics are offered for minimal negation in B+. Certain forms of reductio are conjectured to be undefinable (in ternary frames) without extending the positive logic. Complete semantics for such kinds of reductio in a properly extended positive logic are offered
Planar Realizability via Left and Right Applications
We introduce a class of applicative structures called bi-BDI-algebras. Bi-BDI-algebras are generalizations of partial combinatory algebras and BCI-algebras, and feature two sorts of applications (left and right applications). Applying the categorical realizability construction to bi-BDI-algebras, we obtain monoidal bi-closed categories of assemblies (as well as of modest sets). We further investigate two kinds of comonadic applicative morphisms on bi-BDI-algebras as non-symmetric analogues of linear combinatory algebras, which induce models of exponential and exchange modalities on non-symmetric linear logics
Nondeterministic and nonconcurrent computational semantics for BB+ and related logics
In this paper, we provide a semantics for a range of positive substructural logics, including both logics with and logics without modal connectives. The semantics is novel insofar as it is meant to explicitly capture the computational flavor of these logics, and to do so in a way that builds in both nondeterministic and nonconcurrent computational processes
Information Flow in Logics in the Vicinity of BB
Situation theory, and channel theory in particular, have been used to provide motivational accounts of the ternary relation semantics of relevant, substructural, and various non-classical logics. Among the constraints imposed by channel-theory, we must posit a certain existence criterion for situations which result from the composites of multiple channels (this is used in modeling information flow). In associative non-classical logics, it is relatively easy to show that a certain such condition is met, but the problem is trickier in non-associative logics. Following Tedder (2017), where it was shown that the conjunction-conditional fragment of the logic B admits the existence of composite channels, I present a generalised ver- sion of the previous argument, appropriate to logics with disjunction, in the neighbourhood ternary relation semantic framework. I close by suggesting that the logic BB+(^I), which falls between Lavers' system BB+ and B+ , satisfies the conditions for the general argument to go through (and prove that it satisfies all but one of those conditions)
Information Flow in Logics in the Vicinity of BB
Situation theory, and channel theory in particular, have been used to provide motivational accounts of the ternary relation semantics of relevant, substructural, and various non-classical logics. Among the constraints imposed by channel-theory, we must posit a certain existence criterion for situations which result from the composites of multiple channels (this is used in modeling information flow). In associative non-classical logics, it is relatively easy to show that a certain such condition is met, but the problem is trickier in non-associative logics. Following Tedder (2017), where it was shown that the conjunction-conditional fragment of the logic B admits the existence of composite channels, I present a generalised ver- sion of the previous argument, appropriate to logics with disjunction, in the neighbourhood ternary relation semantic framework. I close by suggesting that the logic BB+(^I), which falls between Lavers' system BB+ and B+ , satisfies the conditions for the general argument to go through (and prove that it satisfies all but one of those conditions)
Categorical Realizability for Non-symmetric Closed Structures
In categorical realizability, it is common to construct categories of
assemblies and categories of modest sets from applicative structures. These
categories have structures corresponding to the structures of applicative
structures. In the literature, classes of applicative structures inducing
categorical structures such as Cartesian closed categories and symmetric
monoidal closed categories have been widely studied. In this paper, we expand
these correspondences between categories with structure and applicative
structures by identifying the classes of applicative structures giving rise to
closed multicategories, closed categories, monoidal bi-closed categories as
well as (non-symmetric) monoidal closed categories. These applicative
structures are planar in that they correspond to appropriate planar lambda
calculi by combinatory completeness. These new correspondences are tight: we
show that, when a category of assemblies has one of the structures listed
above, the based applicative structure is in the corresponding class. In
addition, we introduce planar linear combinatory algebras by adopting linear
combinatory algebras of Abramsky, Hagjverdi and Scott to our planar setting,
that give rise to categorical models of the linear exponential modality and the
exchange modality on the non-symmetric multiplicative intuitionistic linear
logic