35 research outputs found
Multiple Conclusion Rules in Logics with the Disjunction Property
We prove that for the intermediate logics with the disjunction property any
basis of admissible rules can be reduced to a basis of admissible m-rules
(multiple-conclusion rules), and every basis of admissible m-rules can be
reduced to a basis of admissible rules. These results can be generalized to a
broad class of logics including positive logic and its extensions, Johansson
logic, normal extensions of S4, n-transitive logics and intuitionistic modal
logics
On the Concept of a Notational Variant
In the study of modal and nonclassical logics, translations have frequently been employed as a way of measuring the inferential capabilities of a logic. It is sometimes claimed that two logics are “notational variants” if they are translationally equivalent. However, we will show that this cannot be quite right, since first-order logic and propositional logic are translationally equivalent. Others have claimed that for two logics to be notational variants, they must at least be compositionally intertranslatable. The definition of compositionality these accounts use, however, is too strong, as the standard translation from modal logic to first-order logic is not compositional in this sense. In light of this, we will explore a weaker version of this notion that we will call schematicity and show that there is no schematic translation either from first-order logic to propositional logic or from intuitionistic logic to classical logic
Anticlockwise metamorphic pressure–temperature paths and nappe stacking in the Reisa Nappe Complex in the Scandinavian Caledonides, northern Norway: evidence for weakening of lower continental crust before and during continental collision
This study investigates the tectonostratigraphy and metamorphic and tectonic
evolution of the Caledonian Reisa Nappe Complex (RNC; from bottom to top:
Vaddas, Kåfjord, and Nordmannvik nappes) in northern Troms, Norway.
Structural data, phase equilibrium modelling, and U-Pb zircon and titanite
geochronology are used to constrain the timing and pressure–temperature
(P–T) conditions of deformation and metamorphism during nappe stacking
that facilitated crustal thickening during continental collision. Five
samples taken from different parts of the RNC reveal an anticlockwise
P–T path attributed to the effects of early Silurian heating (D1)
followed by thrusting (D2). At ca. 439 Ma during D1 the
Nordmannvik Nappe reached the highest metamorphic conditions at
ca. 780 ∘C and ∼9–11 kbar inducing kyanite-grade partial
melting. At the same time the Kåfjord Nappe was at higher, colder, levels
of the crust ca. 600 ∘C, 6–7 kbar and the Vaddas Nappe was
intruded by gabbro at > 650 ∘C and ca. 6–9 kbar. The
subsequent D2 shearing occurred at increasing pressure and decreasing
temperatures ca. 700 ∘C and 9–11 kbar in the partially molten
Nordmannvik Nappe, ca. 600 ∘C and 9–10 kbar in the Kåfjord
Nappe, and ca. 640 ∘C and 12–13 kbar in the Vaddas Nappe.
Multistage titanite growth in the Nordmannvik Nappe records this evolution
through D1 and D2 between ca. 440 and 427 Ma, while titanite
growth along the lower RNC boundary records D2 shearing at 432±6 Ma. It emerges that early Silurian heating (ca. 440 Ma) probably
resulted from large-scale magma underplating and initiated partial melting
that weakened the lower crust, which facilitated dismembering of the crust
into individual thrust slices (nappe units). This tectonic style contrasts
with subduction of mechanically strong continental crust to great depths as
seen in, for example, the Western Gneiss Region further south.</p
Admissible Bases Via Stable Canonical Rules
We establish the dichotomy property for stable canonical multi-conclusion rules for IPC, K4, and S4. This yields an alternative proof of existence of explicit bases of admissible rules for these logics
Proof Complexity of Non-classical Logics.
Proof complexity is an interdisciplinary area of research utilizing techniques from logic, complexity, and combinatorics towards the main aim of understanding the complexity of theorem proving procedures. Traditionally, propositional proofs have been the main object of investigation in proof complexity. Due their richer expressivity and numerous applications within computer science, also non-classical logics have been intensively studied from a proof complexity perspective in the last decade, and a number of impressive results have been obtained. In this paper we give the rst survey of this eld concentrating on recent developments in proof complexity of non-classical logics
Catalytic Activity and Accessibility of Acidic Ion-Exchange Resins in Liquid Phase Etherification Reactions
Technical means using by Customs administration of the Czech Republic to detection of narcotic and psychoactive drugs.
Autor v úvodu své práce krátce hodnotí vývoj problematiky užívání a zneužívání omamných a psychotropních látek na našem území a popisuje jednotlivé technické prostředky používané v minulosti a současnosti k jejich vyhledávání a detekci. Cílem práce je vymezení způsobu použití technických prostředků v praxi, vhodnosti jejich použití v konkrétních podmínkách výkonu služby a nové trendy ve vývoji a využití těchto prostředků