An example is given of a software algorithm that implements its specification in linear time temporal logic (LTL), but not branching (CTL). In LTL, prophecy future behaviour needed to prove the simulation. Eternity variables are used for this purpose. The final phase proof refinement mapping which two threads exchange roles. implementation trylock variation fast mutual exclusion Lamport (1987)....

The concept and technics of real space renormalization group are applied to study majority rule voting in hierarchical structures. It is found that democratic voting can lead to totalitarianism by keeping in power a small minority. Conditions of this paradox are analyzed and singled out. Indeed majority rule produces critical thresholds to absolute power. Values of these thresholds can vary fro...

In his recent book, From Eternity to Here, and in other more technical papers, Sean Carroll (partly in collaboration with Jennifer Chen) has put forward an intriguing new way to think about the origin of the Universe. His approach, in a nutshell, is to raise certain worries about a standard Boltzmannian picture of statistical mechanics, and to present certain commitments that he thinks we ought...

In this country any chemist or druggist can furnish the means of self-destruction or murder for a few pence, and in too many instances have done so with the utmost indifference. The sale of a poison is regarded as a mere act of commercial intercourse; tant pis for the unfortunate victim of error or passion; he has the benefit of a coroner's inquest; the vendor of the poison receives a reprimand...

We all have a dream: all of us want to live a long, healthy, and successful life in full possession of our physical and mental faculties, surrounded by family and friends. We all want to be respected, to feel that we are needed, and to be useful and happy at work and in family life. Lives cut off before their time, people we care for often, and increasingly leaving us for eternity while young o...