A sound and complete proof system for separation logic (part 1) Download the PDF version of this article.

Can the Collatz conjecture be proven, or not? Download the PDF version of this article. collatz.pdf 236 KB In 1937, shortly after the mathematician Lothar Collatz obtained his doctorate, he wrote down a problem in his notebook that later became known as Collatz’ problem or the \(3x+1)\-problem . The problem is remarkable since it is easy to state, but for more than eighty years no solution had been found.