On Invariance and InconsistencyDownload the PDF version of this article.invariance-inconsistency.pdf301 KB.a{fill:none;stroke:currentColor;stroke-linecap:round;stroke-linejoin:round;stroke-width:1.5px;}download-circle How can you explain important concepts from program correctness in a simple and intuitive manner? In this blog post, we shall have a look at some puzzles and analyze them from the perspective of program correctness.

Can the Collatz conjecture be proven, or not?Download the PDF version of this article.collatz.pdf236 KB.a{fill:none;stroke:currentColor;stroke-linecap:round;stroke-linejoin:round;stroke-width:1.5px;}download-circle 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

Correctness of Two Sorting AlgorithmsDownload the PDF version of this article.two-sorting-algorithms.pdf200 KB.a{fill:none;stroke:currentColor;stroke-linecap:round;stroke-linejoin:round;stroke-width:1.5px;}download-circle On Wednesday, 8th of March, 2023, I gave a lecture about two sorting algorithms for the course Program Correctness (see also the lecture series on YouTube, available only in Dutch). Then, due to limited time, I only discussed a