The paper discusses the development of an IBM PC based tool, for calculating train braking distances for various train classes on a rail network. There is discussion on current industry practice and the limitations of that practice, the concept of the tool itself, including the assumptions made, the strategy adopted to minimise the risk of incorrect calculations, and the results of adopting tha...

A further commercially available encryption package for the IBM PC is analysed, and a simple breaking program is described.

in this paper we formulate and prove some xed and common xed pointtheorems for self-mappings de ned on complete lower transversal functionalprobabilistic spaces.