Programming Languages and Systems

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.

Inhalt
Semantics and Analysis.- An Algebraic Theory for Shared-State Concurrency.- Decoupling the Ascending and Descending Phases in Abstract Interpretation.- Inferring Region Types via an Abstract Notion of Environment Transformation.- Testing and Verification.- RHLE: Modular Deductive Verification of Relational Properties.- Automated Temporal Verification for Algebraic Effects.- Model-based Fault Classification for Automotive Software.- Types.- Characterizing functions mappable over GADTs.- Applicative Intersection Types.- A Calculus with Recursive Types, Record Concatenation and Subtyping.- Novice Type Error Diagnosis with Natural Language Models.