Wim Schikhof: our colleague and friend

The first of May 2014, Wim Schikhof passed away in Nijmegen, The Netherlands, after a long illness at the age of seventy-six. He played a crucial role in the construction of the pillars of p-Adic (Functional) Analysis, as well as in the development of this area of Mathematics. For many people, among them the authors of this paper, he was also a good colleague and friend, whom we just called Wim, although his official first name was Wilhelmus Hendricus. We feel proud to honor him by this article, acting on behalf of the "p-Adic community".