This book constitutes the refereed proceedings of the 26th International Conference on Practical Aspects of Declarative Languages, PADL 2024, held in London, UK, during January 17–19, 2024.The 13 full papers included in this book were carefully reviewed and selected from 25 submissions. The accepted papers span a range of topics related to functional and logic programming, including reactive programming, hardware implementations, implementation of marketplaces, query languages, and...

This book constitutes the proceedings of the 20th Asian Symposium on Programming Languages and Systems, APLAS 2022, held in Auckland, New Zealand, in December 2022.The 10 papers presented in this volume were carefully reviewed and selected from 22 submissions. They were organized in topical sections as follows: Semantics and Analysis; Testing and Verification; Types.