Formal methods have been successfully used to establish assurances for safety-critical systems with mathematical rigour. Based on our experience in developing a methodology and corresponding tools for a change management for formal methods, we have generalised this approach to a comprehensive methodology to maintain heterogeneous document collections consisting of both formal and informal docum...

The main result of this article is that for collections of entry-wise non-negative matrices the property of possessing a standard triangularization is stable under approximation. The methodology introduced to prove this result allows us to offer quick proofs of the corresponding results of [B. R. Yahaghi, Near triangularizability implies triangularizability, Canad. Math. Bull. 47, (2004), no. 2...

Since its original formulation, the theory of fuzzy sets has spawned a number of extensions where the role of membership values in the real unit interval $[0, 1]$ is handed over to more complex mathematical entities. Amongst the many existing extensions, two similar ones, the fuzzy multisets and the hesitant fuzzy sets, rely on collections of several distinct values to represent fuzzy membershi...

Information seekers are generally on their own to discover and use a research library’s growing array of digital collections, and coordination of these collections’ development and maintenance is often not optimal. The frequent lack of a conscious design for how collections fit together is of equal concern because it means that research libraries are not making the most of the substantial inves...