“…𝖷𝖢 can be framed in the context of a long-term research thread on programming languages and tools for programming collective adaptive systems, known under the umbrella terms of field-based coordination (Mamei and Zambonelli, 2006;Viroli et al, 2019) and aggregate computing (Beal et al, 2015;Viroli et al, 2019). This research area is characterised by works on formal calculi (Audrito et al, 2019(Audrito et al, , 2023a, new constructs (Audrito et al, 2020;Casadei et al, 2019), formal properties of programs and computations (Viroli et al, 2018;Beal et al, 2017;Audrito et al, 2018a), programming language implementations of formal calculi as DSLs (Casadei et al, 2022b(Casadei et al, , 2021Audrito, 2020), simulators (Pianini et al, 2013;Audrito et al, 2022e), algorithms and patterns (Beal, 2009;Audrito et al, 2017b,a;Pianini et al, 2021b;Audrito et al, 2021a;Pianini et al, 2022), execution models (Pianini et al, 2021a), distributed platforms and deployments (Casadei et al, 2020(Casadei et al, , 2022a, and libraries for application domains such as swarm robotics (Aguzzi et al, 2023) and distributed monitoring (Audrito et al, 2021b). In a nutshell, this work proposes a new calculus, 𝖷𝖢, inspired by previous calculi, that subsumes them and is strictly more expressive in its ability to model messages differentiated on a neighbour basis (see Section 8.3 for a more detailed comparison).…”