Testing for grammatical coverings

Bounds for Optimal Coverings

We give bounds for optimal coverings of finite sets by elements of regular families of subsets, and show that both upper and lower bounds are asymptotically sharp for some families of examples.

Index Theory for Coverings

Fractional Coverings, Greedy Coverings, and Rectifier Networks

A rectifier network is a directed acyclic graph with distinguished sources and sinks; it is said to compute a Boolean matrix M that has a 1 in the entry (i, j) iff there is a path from the jth source to the ith sink. The smallest number of edges in a rectifier network that computes M is a classic complexity measure on matrices, which has been studied for more than half a century. We explore two...

Testing For Efficiency Wages In Iran

On category of co-coverings

In this article, we introduce the concept of co-covering which is the dual of covering concept. Then, we prove several theorems being similar to the theorems that have been de-veloped for the covering concept. For example, we provide the lifting criterion for co-coverings of a topological space X, which helps us to classify them by subgroups of the group of all homeomorphisms of X.