Programming Languages and Systems 35th European Symposium on Programming, ESOP 2026, Held as Part of the International Joint… (Robbert Krebbers)（Z-Library）

# Programming Languages and Systems: ESOP 2026 Proceedings ## 【One-Line Pitch】 A collection of 31 peer-reviewed research papers from the 35th European Symposium on Programming, covering cutting-edge work in programming language theory, type systems, concurrency semantics, and formal verification. Essential reading for programming language researchers, graduate students in theoretical computer science, and practitioners working on formal methods and verified systems. ## 【Book Arc】 - **Opening (~0%–3%)**: Front matter establishes the ESOP 2026 context—31 papers selected from 94 submissions, held at ETAPS 2026 in Turin. The invited talk introduces formal methods for digital twins, framing the volume's emphasis on rigorous specification and verification. - **Early (~3%–13%)**: The first major paper develops **contextual metaprogramming for session types**, combining staged computation with communication protocol typing. The PrimeTask example shows how session types govern task assignment while metaprogramming sends code updates, with applications to computation offloading for resource-constrained devices. - **Early (~13%–23%)**: A second thread examines **RDMA synchronization semantics**, contrasting brittle polling mechanisms with compositional waiting abstractions. The rdmatso model reveals how remote operations execute asynchronously, and the loco library's work-identifier approach enables modular verification. - **Early (~23%–32%)**: Formal specification of RDMA synchronization continues with **strong versus node locks**, showing how different lock granularities affect memory consistency guarantees. The distinction between global and node-local synchronization is formalized through nlock-consistency conditions. - **Middle (~39%–48%)**: A shift to **topos theory and dependent type theory**, exploring how sheaf semantics and forcing conditions interpret inductive types. The Cantor space serves as a running example for compactness arguments, with quotient inductive types providing syntactic equivalents to Grothendieck topos constructions. - **Middle (~48%)**: The MLTTϝ calculus extends Martin-Löf type theory with **oracle-based forcing conditions**, where a state of knowledge ℓ is reflected into conversion rules. This enables reasoning about functions on the Cantor space within a mechanized type theory framework. ## 【Key Takeaways】 - **Session types can be combined with staged metaprogramming** (Early): The paper demonstrates how box types and contextual terms let programs send code over typed communication channels, enabling dynamic code updates in distributed systems. This matters for computation offloading scenarios where resource-constrained devices transfer tasks to servers. - **RDMA polling semantics are fundamentally non-compositional** (Early): The rdmatso model shows that polling synchronizes with the earliest unpolled remote operation, meaning correctness depends on counting operations globally. This brittleness motivates the need for more abstract completion mechanisms. - **Work identifiers provide compositional RDMA synchronization** (Early): The loco library's Wait(d) operation associates remote operations with identifiers, making synchronization behavior independent of unrelated operations. This enables modular programming and verification that polling cannot offer. - **Node locks offer intermediate synchronization granularity** (Early): Between global strong locks and no synchronization, node locks protect accesses to specific remote nodes, providing weaker but more scalable guarantees. The formal nlock-consistency conditions precisely characterize these trade-offs. - **Topos theory provides a semantic home for dependent type theory** (Middle): Grothendieck toposes interpret inductive types, and quotient inductive types give syntactic equivalents. This connection matters for understanding how type theories relate to categorical semantics. - **Forcing conditions can be internalized as oracle-based conversion rules** (Middle): The MLTTϝ calculus extends Martin-Löf type theory with a state of knowledge that participates in definitional equality, enabling reasoning about compact spaces like the Cantor space within the theory itself. - **Tychonoff's theorem connects compactness to choice principles** (Middle): The compactness of Cantor space and its logical consequences (model existence for propositional theories) illustrate deep links between topology, logic, and set theory that inform the type-theoretic constructions. ## 【Reading Tips】 - **Skim the front matter and invited talk** (~0%–3%): These establish context but contain no technical content. The digital twins discussion is accessible and frames the volume's practical motivations. - **Deep-read the session types paper** (~3%–13%): The typing rules in Figures 11–12 are dense but central. Focus on understanding the context split operation and how box types interact with linear resources before attempting the full formalism. - **For the RDMA papers** (~13%–32%): Start with the intuitive examples (Figures 2–3, 12) before tackling the formal definitions. The distinction between polling and waiting, and between strong and node locks, is best grasped through the concrete scenarios. - **The topos theory section** (~39%–48%) assumes significant background: familiarity with sheaves, forcing, and dependent type theory. If you lack this, skim for the high-level claims about quotient inductive types and the MLTTϝ oracle rules rather than attempting full comprehension. - **Skip the reference lists** unless you need to trace specific prior work; the papers are self-contained for their main contributions. ## 【Coverage Limits】 The excerpts cover roughly the first half of the proceedings (approximately 48% of the book). The remaining papers—covering topics like programming paradigms, program reasoning tools, and systems design—are not represented in this guide. Additionally, the full technical details of several formal systems are only partially visible in the excerpts. ##