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Causal models of agents have been used to analyse the safety aspects of machine learning systems. But identifying agents is non-trivial – often the causal model is just assumed by the modeller without much justification – and modelling failures can lead ...

Causal models of agents have been used to analyse the safety aspects of machine learning systems. But identifying agents is non-trivial – often the causal model is just assumed by the modeller without much justification – and modelling failures ...

• First formal causal definition of agents.
• First causal discovery algorithm for discovering agents from empirical data.
• Algorithms for translating between causal models and game-theoretic influence diagrams.
• Resolves confusions ...

We have extended the verified CakeML compiler with a new language primitive, Eval, which permits evaluation of new CakeML syntax at runtime. This new implementation supports an ambitious form of compilation at runtime and dynamic execution, where ...

We implement an automated tactical prover TacticToe on top of the HOL4 interactive theorem prover. TacticToe learns from human proofs which mathematical technique is suitable in each proof situation. This knowledge is then used in a Monte Carlo ...

We introduce an automatic method for producing stateful ML programs together with proofs of correctness from monadic functions in HOL. Our mechanism supports references, exceptions, and I/O operations, and can generate functions manipulating local ...

Developing technology for building verified stacks, i.e., computer systems with comprehensive proofs of correctness, is one way the science of programming languages furthers the computing discipline. While there have been successful projects verifying ...

Software verification tools that build machine-checked proofs of functional correctness usually focus on the algorithmic content of the code. Their proofs are not grounded in a formal semantic model of the environment that the program runs in, or ...

We introduce a new framework for verifying electronic vote counting results that are based on the Single Transferable Vote scheme (STV). Our approach frames electronic vote counting as certified computation where each execution of the counting ...

We have designed an intermediate language (IL) for the CakeML compiler that supports the verified, efficient compilation of functions and calls. Verified compilation steps include batching of multiple curried arguments, detecting calls to statically ...

Characteristic Formulae (CF) offer a productive, principled approach to generating verification conditions for higher-order imperative programs, but so far the soundness of CF has only been considered with respect to an informal specification of a ...

This paper describes how the latest CakeML compiler supports verified compilation down to multiple realistically modelled target architectures. In particular, we describe how the compiler definition, the various language semantics, and the correctness ...

We have developed and mechanically verified a new compiler backend for CakeML. Our new compiler features a sequence of intermediate languages that allows it to incrementally compile away high-level features and enables verification at the right levels ...

When doing an interactive proof about a piece of software, it is important that the underlying programming language's semantics does not make the proof unnecessarily difficult or unwieldy. Both small-step and big-step semantics are commonly used, and the ...

We present a mechanised semantics for higher-order logic (HOL), and a proof of soundness for the inference system, including the rules for making definitions, implemented by the kernel of the HOL Light theorem prover. Our work extends Harrison's ...

CakeML is a dialect of the (strongly typed) ML family of programming languages, designed to play a central role in high-assurance software systems. To date, the main artefact supporting this is a verified compiler from CakeML source code to x86-64 ...

We have developed and mechanically verified an ML system called CakeML, which supports a substantial subset of Standard ML. CakeML is implemented as an interactive read-eval-print loop (REPL) in x86-64 machine code. Our correctness theorem ensures that ...

This short paper describes our plans and progress towards construction of verified ML implementations of HOL Light: the first formally proved soundness result for an LCF-style prover. Building on Harrison's formalisation of the HOL Light logic and our ...

We describe a collaborative effort in which the HOL4 theorem prover is being used to formally verify properties of a structure within the Large Hadron Collider (LHC) machine protection system at the European Organization for Nuclear Research (CERN). ...

The Quantified Boolean Formulae (QBF) solver Squolem can generate certificates of validity, based on Skolem functions. We present independent checking of these certificates in the HOL4 theorem prover. This enables HOL4 users to benefit from Squolem's ...

Using HOL4, we mechanise termination and correctness for two unification algorithms, written in a recursive descent style. One computes unifiers for first order terms, the other for nominal terms (terms including α-equivalent binding structure). Both ...