Invited Talks -- Whats and Whys of Neural Network Verification (A Declarative Programming Perspective) -- Modular Higher-Order Effects -- Regular Papers -- Forget and Regeneration Techniques for Optimizing ASP-based Stream Reasoning -- Asynchronous Reactive Programming with Modal Types in Haskell -- FOLD-SE: An Efficient Rule-based Machine Learning Algorithm with Scalable Explainability -- Marketplace Logistics via Answer Set Programming -- Rhyme: A Data-Centric Expressive Query Language for Nested Data Structures -- Rethinking Answer Set Programming Templates -- Cutting the Cake Into Crumbs: Verifying Envy-Free Cake-Cutting Protocols using Bounded Integer Arithmetic -- A direct ASP Encoding for Declare -- Using Logic Programming and Kernel-Grouping for Improving Interpretability of Convolutional Neural Networks -- Hardware implementation of OCaml using a synchronous functional language -- Ontological Reasoning over Shy and Warded Datalog+/- for Streaming-based Architectures -- Explanation and Knowledge Acquisition in Ad Hoc Teamwork -- Automated Interactive Domain-Specific Conversational Agents that Understand Human Dialogs.

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 applications of declarative programming techniques to artificial intelligence and machine learning.