Ordering constraints over feature trees expressed in second-order monadic logic

1998 ◽  
pp. 196-210 ◽  
Author(s):  
Martin Müller ◽  
Joachim Niehren
Keyword(s):  
Second Order ◽  
Ordering Constraints ◽  
Monadic Logic ◽  
Feature Trees

scholarly journals The First-Order Theory of Ordering Constraints over Feature Trees

2001 ◽  
Vol Vol. 4 no. 2 ◽  
Author(s):  
Martin Müller ◽  
Joachim Niehren ◽  
Ralf Treinen
Keyword(s):  
Finite Automata ◽  
Order Theory ◽  
Inclusion Problem ◽  
First Order ◽  
First Order Theory ◽  
Infinite Trees ◽  
Ordering Constraints ◽  
International Audience ◽  
Existential Quantification ◽  
Feature Trees

International audience The system FT< of ordering constraints over feature trees has been introduced as an extension of the system FT of equality constraints over feature trees. We investigate the first-order theory of FT< and its fragments in detail, both over finite trees and over possibly infinite trees. We prove that the first-order theory of FT< is undecidable, in contrast to the first-order theory of FT which is well-known to be decidable. We show that the entailment problem of FT< with existential quantification is PSPACE-complete. So far, this problem has been shown decidable, coNP-hard in case of finite trees, PSPACE-hard in case of arbitrary trees, and cubic time when restricted to quantifier-free entailment judgments. To show PSPACE-completeness, we show that the entailment problem of FT< with existential quantification is equivalent to the inclusion problem of non-deterministic finite automata. Available at http://www.ps.uni-saarland.de/Publications/documents/FTSubTheory_98.pdf

A Logical Characterisation of Event Clock Automata

2003 ◽  
Vol 14 (04) ◽  
pp. 625-639 ◽  
Author(s):  
Deepak D'souza
Keyword(s):  
Temporal Logic ◽  
Second Order ◽  
Order Logic ◽  
Monadic Logic ◽  
Second Order Logic ◽  
Monadic Second Order Logic

We show that the class of Event Clock Automata [2] admit a logical characterisation via an unrestricted monadic second order logic interpreted over timed words. The result is interesting in that it provides an unrestricted yet decidable logical characterisation of a non-trivial class of timed languages. A timed temporal logic considered earlier in the literature [11] is shown to be expressively complete with respect to the monadic logic.

Names, Verbs and Sentences

Philosophy ◽  
1998 ◽  
Vol 73 (4) ◽  
pp. 619-623
Author(s):  
Nicholas Denyer
Keyword(s):  
Second Order ◽  
Monadic Logic

Metaphysicians often declare that there are large ontological differences (properties versus individuals, universals versus particulars) correlated with the linguistic distinction between names and verbs. Gaskin argues against all such declarations on the grounds that we may quantify with equal ease over the referents of both types of expression. However, his argument must be wrong, given the massive differences between first- and second-order qualification. Its only grain of truth is that these differences show up only in the logic of relations, and not also in monadic logic.

scholarly journals Groups, graphs, languages, automata, games and second-order monadic logic

2012 ◽  
Vol 33 (7) ◽  
pp. 1330-1368 ◽  
Author(s):  
Tullio Ceccherini-Silberstein ◽  
Michel Coornaert ◽  
Francesca Fiorenzi ◽  
Paul E. Schupp
Keyword(s):  
Second Order ◽  
Monadic Logic

Disappearance Voltage Determinations Using a Convergent Beam

1971 ◽  
Vol 29 ◽  
pp. 184-185
Author(s):  
W. L. Bell
Keyword(s):  
Second Order ◽  
Objective Method ◽  
Uniform Thickness ◽  
Rocking Curve ◽  
Crystal Perfection ◽  
Kikuchi Line ◽  
Central Maximum ◽  
Diffraction Patterns ◽  
Convergent Beam ◽  
Beam Technique

Disappearance voltages for second order reflections can be determined experimentally in a variety of ways. The more subjective methods, such as Kikuchi line disappearance and bend contour imaging, involve comparing a series of diffraction patterns or micrographs taken at intervals throughout the disappearance range and selecting that voltage which gives the strongest disappearance effect. The estimated accuracies of these methods are both to within 10 kV, or about 2-4%, of the true disappearance voltage, which is quite sufficient for using these voltages in further calculations. However, it is the necessity of determining this information by comparisons of exposed plates rather than while operating the microscope that detracts from the immediate usefulness of these methods if there is reason to perform experiments at an unknown disappearance voltage.The convergent beam technique for determining the disappearance voltage has been found to be a highly objective method when it is applicable, i.e. when reasonable crystal perfection exists and an area of uniform thickness can be found. The criterion for determining this voltage is that the central maximum disappear from the rocking curve for the second order spot.

Sign in / Sign up

Export Citation Format

Share Document