Discover the foundations of computer science.

Hans-Dieter Hiep

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
<em>
 Collatz’ problem
</em>
or
<em>
 the \(3x+1)\-problem
</em>
. The problem is remarkable since it is easy to state, but for more than eighty years no solution had been found.

Can the Collatz conjecture be proven, or not?

In university, one sees students attending lectures and labs, working together on assignments, and doing exams. But—standing still for a moment—what is the purpose of all this business? The answer involves education, in the sense that students are being educated. But what is an education, precisely? In this blog post, I will summarize my views on the matter. Some say that an education is more than professional training.

What is an education?

In this post, I'll publish the answers given by OpenAI's ChatGPT for the final exam of the course Concepts of Programming Languages, a course I gave in the fall semester of 2022.

Can ChatGPT do an exam?

Frank de Boer

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

A sound and complete proof system for separation logic (part&nbsp;1)

Correctness of Two Sorting Algorithms  Download the PDF version of this article. two-sorting-algorithms.pdf  200 KB    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 sketch of the correctness proof.

Correctness of Two Sorting Algorithms

On Invariance and Inconsistency  Download the PDF version of this article. invariance-inconsistency.pdf  301 KB    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.

dr. heap

On Invariance and Inconsistency

Correctness of Two Sorting Algorithms