Articles

A collection of articles on topics related to foundations of computer science, including logic, programming language theory, and program correctness.

2025

2024

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

Original Research

Program Correctness

A novel proof system for separation logic is explained.

Hans-Dieter A. Hiep, Frank S. Boer

On invariance and inconsistency

Lecture Notes

Program Correctness

Program correctness is not easy: the requirements of a program may be inconsistent, or there may not even exist a correct program that satisfies the requirements. This article works out two concrete cases.

Hans-Dieter A. Hiep

2023

Can the Collatz conjecture be proven, or not?

Reviewed Research

Program Correctness

We review a recent preprint article about the Collatz conjecture. The Collatz conjecture is a more than eighty years old problem that is still unsolved.

Hans-Dieter A. Hiep

What is an education?

Opinion

Teaching

This article describes what I think is the essence of education.

Hans-Dieter A. Hiep

Correctness of two sorting algorithms

Lecture Notes

Program Correctness

This article describes two sorting algorithms (gnome sort and bozosort) and gives their correctness proof in full detail.

Hans-Dieter A. Hiep

Can ChatGPT do an exam?

Teaching

Artificial Intelligence

In this article we have a look at ChatGPT’s answers to the final exam of a course I taught in 2022.

Hans-Dieter A. Hiep