Boolean and classical restriction categories

2009 ◽  
Vol 19 (2) ◽  
pp. 357-416 ◽  
Author(s):  
ROBIN COCKETT ◽  
ERNIE MANES

A restriction category is an abstract category of partial maps. A Boolean restriction category is a restriction category that supports classical (Boolean) reasoning. Such categories are models of loop-free dynamic logic that is deterministic in the sense that < α > Q ⊂ [α]Q. Classical restriction categories are restriction categories with a locally Boolean structure: it is shown that they are precisely full subcategories of Boolean restriction categories. In particular, a Boolean restriction category may be characterised as a classical restriction category with finite coproducts in which all restriction idempotents split.Every restriction category admits a restriction embedding into a Boolean restriction category. Thus, every abstract category of partial maps admits a conservative extension that supports classical reasoning. An explicit construction of the classical completion of a restriction category is given.

1987 ◽  
Vol 10 (2) ◽  
pp. 123-141
Author(s):  
Pawel Urzyczyn

We show an example of an algebra T∙, such that every flow-chart program is equivalent in T∙ to a loop-free approximation of itself, while a program augmented by one binary push-down store is not equivalent in T∙ to any loop-free program. From this we deduce that the Deterministic Dynamic Logic of regular programs is strictly weaker than the Deterministic Context-Free Dynamic Logic.


10.29007/smg4 ◽  
2018 ◽  
Author(s):  
Ping Hou ◽  
Yifei Chen

We introduce a logic for specifying and verifying metric temporal properties of distributed hybrid systems that combines quantified differential dynamic logic (QdL) for reasoning about the possible behavior of distributed hybrid systems with metric temporal logic (MTL) for reasoning about the metric temporal behavior during their operation. For our combined logic, we generalize the semantics of dynamic modalities to refer to hybrid traces instead of final states. Further, we prove that this gives a conservative extension of QdL for distributed hybrid systems. On this basis, we provide a modular verification calculus that reduces correctness of metric temporal behavior of distributed hybrid systems to generic temporal reasoning and then non-temporal reasoning, and prove that we obtain a complete axiomatization relative to the non-temporal base logic QdL.


2002 ◽  
Vol 67 (3) ◽  
pp. 933-946 ◽  
Author(s):  
Tomasz Kowalski

AbstractIt is proved that free dynamic algebras superamalgamate. Craig interpolation for propositional dynamic logic and superamalgamation for the variety of dynamic algebras follow.


2020 ◽  
Vol 8 ◽  
pp. 740-747 ◽  
Author(s):  
Jens Trommer ◽  
Maik Simon ◽  
Stefan Slesazeck ◽  
Walter M. Weber ◽  
Thomas Mikolajick

Author(s):  
Deepika Bansal ◽  
Bal Chand Nagar ◽  
Brahamdeo Prasad Singh ◽  
Ajay Kumar

Background & Objective: In this paper, a modified pseudo domino configuration has been proposed to improve the leakage power consumption and Power Delay Product (PDP) of dynamic logic using Carbon Nanotube MOSFETs (CN-MOSFETs). The simulations for proposed and published domino circuits are verified by using Synopsys HSPICE simulator with 32nm CN-MOSFET technology which is provided by Stanford. Methods: The simulation results of the proposed technique are validated for improvement of wide fan-in domino OR gate as a benchmark circuit at 500 MHz clock frequency. Results: The proposed configuration is suitable for cascading of the high performance wide fan-in circuits without any charge sharing. Conclusion: The performance analysis of 8-input OR gate demonstrate that the proposed circuit provides lower static and dynamic power consumption up to 62 and 40% respectively, and PDP improvement is 60% as compared to standard domino circuit.


2021 ◽  
Vol 11 (10) ◽  
pp. 4420
Author(s):  
Panayotis Panayotaros

We study properties of an infinite system of discrete nonlinear Schrödinger equations that is equivalent to a coupled Schrödinger-elliptic differential equation with periodic coefficients. The differential equation was derived as a model for laser beam propagation in optical waveguide arrays in a nematic liquid crystal substrate and can be relevant to related systems with nonlocal nonlinearities. The infinite system is obtained by expanding the relevant physical quantities in a Wannier function basis associated to a periodic Schrödinger operator appearing in the problem. We show that the model can describe stable beams, and we estimate the optical power at different length scales. The main result of the paper is the Hamiltonian structure of the infinite system, assuming that the Wannier functions are real. We also give an explicit construction of real Wannier functions, and examine translation invariance properties of the linear part of the system in the Wannier basis.


2003 ◽  
Vol 3 (2) ◽  
pp. 99-108
Author(s):  
Kermit G. Davis ◽  
Riley E. Splittstoesser ◽  
William S. Marras

Although there have been numerous studies evaluating the difference between stooped and squat lifting styles, there remains a lack of understanding of whole body kinematics during unrestricted lifting. The current study evaluated nine males and nine females while lifting two box weights (9.1 kg, 18.2 kg) from five origins below the waist (0, 19, 38, 57, and 76 cm above the floor) and from three task asymmetries (sagittally symmetric, 45° clockwise, 45° counter-clockwise). While the lifting style was significantly influenced by the height of lift origin and to a lesser extent gender, box weight, and task asymmetry, none of the conditions resulted in pure squat or stoop lifting style. However, for lifts above knee height, the lifting style resembled more of a stoop lift while lifts originating below knee height were more of a squat lift. As the origin moved closer to the floor, participants relied more on their hips to accomplish the sagittal flexion but overall adopted a more coordinated whole-body lifting style. All together, as more sagittal flexion is required, more joints are relied upon in a more coordinated effort. The current study indicates that caution needs to be exercised when applying results of pure squat or pure stoop lifting studies to free-style (realistic) lifting.


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