This work was funded in part by Arm. This work was supported in part by the Innovate UK project Digital Security by Design (DSbD) Technology Platform Prototype, 105694. This work was funded in part by UK Research and Innovation (UKRI) under the UK government’s Horizon Europe funding guarantee for ERC-AdG-2022, EP/Y035976/1 SAFER. This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No 789108, ERC-AdG-2017 ELVER). Funded by the European Union. Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the European Research Council Executive Agency. Neither the European Union nor the granting authority can be held responsible for them. The authors would like to thank the Isaac Newton Institute for Mathematical Sciences, Cambridge, for support and hospitality during the programme Big Specification, where work on this paper was undertaken. This work was supported by EPSRC grant EP/Z000580/1.