Logic & Formal Reasoning
AlgoPilot: Fully Autonomous Program Synthesis Without Human-Written Programs
Program synthesis has traditionally relied on human-provided specifications, examples, or prior knowledge to generate functional algorithms. Existing methods either emulate human-written algorithms or solve specific tasks without generating reusable programmatic logic, limiting their ability to create novel algorithms. We introduce AlgoPilot, a groundbreaking approach for fully automated program synthesis without human-written programs or trajectories. AlgoPilot leverages reinforcement learning (RL) guided by a Trajectory Language Model (TLM) to synthesize algorithms from scratch. The TLM, trained on trajectories generated by random Python functions, serves as a soft constraint during the RL process, aligning generated sequences with patterns likely to represent valid algorithms. Using sorting as a test case, AlgoPilot demonstrates its ability to generate trajectories that are interpretable as classical algorithms, such as Bubble Sort, while operating without prior algorithmic knowledge. This work establishes a new paradigm for algorithm discovery and lays the groundwork for future advancements in autonomous program synthesis.
Cause
Kungurtsev, Vyacheslav, Moore, Leonardo Christov, Sir, Gustav, Krutsky, Martin
Causal Learning has emerged as a major theme of AI in recent years, promising to use special techniques to reveal the true nature of cause and effect in a number of important domains. We consider the Epistemology of learning and recognizing true cause and effect phenomena. Through thought exercises on the customary use of the word ''cause'', especially in scientific domains, we investigate what, in practice, constitutes a valid causal claim. We recognize the word's uses across scientific domains in disparate form but consistent function within the scientific paradigm. We highlight fundamental distinctions of practice that can be performed in the natural and social sciences, highlight the importance of many systems of interest being open and irreducible and identify the important notion of Hermeneutic knowledge for social science inquiry. We posit that the distinct properties require that definitive causal claims can only come through an agglomeration of consistent evidence across multiple domains and levels of abstraction, such as empirical, physiological, biochemical, etc. We present Cognitive Science as an exemplary multi-disciplinary field providing omnipresent opportunity for such a Research Program, and highlight the main general modes of practice of scientific inquiry that can adequately merge, rather than place as incorrigibly conflictual, multi-domain multi-abstraction scientific practices and language games.
Deontic Temporal Logic for Formal Verification of AI Ethics
Ensuring ethical behavior in Artificial Intelligence (AI) systems amidst their increasing ubiquity and influence is a major concern the world over. The use of formal methods in AI ethics is a possible crucial approach for specifying and verifying the ethical behavior of AI systems. This paper proposes a formalization based on deontic logic to define and evaluate the ethical behavior of AI systems, focusing on system-level specifications, contributing to this important goal. It introduces axioms and theorems to capture ethical requirements related to fairness and explainability. The formalization incorporates temporal operators to reason about the ethical behavior of AI systems over time. The authors evaluate the effectiveness of this formalization by assessing the ethics of the real-world COMPAS and loan prediction AI systems. Various ethical properties of the COMPAS and loan prediction systems are encoded using deontic logical formulas, allowing the use of an automated theorem prover to verify whether these systems satisfy the defined properties. The formal verification reveals that both systems fail to fulfill certain key ethical properties related to fairness and non-discrimination, demonstrating the effectiveness of the proposed formalization in identifying potential ethical issues in real-world AI applications.
Neural DNF-MT: A Neuro-symbolic Approach for Learning Interpretable and Editable Policies
Baugh, Kexin Gu, Dickens, Luke, Russo, Alessandra
Although deep reinforcement learning has been shown to be effective, the model's black-box nature presents barriers to direct policy interpretation. To address this problem, we propose a neuro-symbolic approach called neural DNF-MT for end-to-end policy learning. The differentiable nature of the neural DNF-MT model enables the use of deep actor-critic algorithms for training. At the same time, its architecture is designed so that trained models can be directly translated into interpretable policies expressed as standard (bivalent or probabilistic) logic programs. Moreover, additional layers can be included to extract abstract features from complex observations, acting as a form of predicate invention. The logic representations are highly interpretable, and we show how the bivalent representations of deterministic policies can be edited and incorporated back into a neural model, facilitating manual intervention and adaptation of learned policies. We evaluate our approach on a range of tasks requiring learning deterministic or stochastic behaviours from various forms of observations. Our empirical results show that our neural DNF-MT model performs at the level of competing black-box methods whilst providing interpretable policies.
Model Checking in Medical Imaging for Tumor Detection and Segmentation
Elfatimi, Elhoucine, fatimi, Lahcen El
Abstract--Recent advancements in model checking have demonstrated significant potential across diverse applications, particularly in signal and image analysis. Medical imaging stands out as a critical domain where model checking can be effectively applied to design and evaluate robust frameworks. These frameworks facilitate automatic and semi-automatic delineation of regions of interest within images, aiding in accurate segmentation. This paper provides a comprehensive analysis of recent works leveraging spatial logic to develop operators and tools for identifying regions of interest, including tumorous and non-tumorous areas. Additionally, we examine the challenges inherent to spatial model-checking techniques, such as variability in ground truth data and the need for streamlined procedures suitable for routine clinical practice. Model checking is the process of verifying whether a given structure satisfies a specified logical formula. This concept is general and applies to a wide range of logics and system designs. A fundamental model-checking problem involves determining whether a propositional logic equation is satisfied by a given structure. Model checking is most commonly applied to hardware designs. For software systems, due to undecidability, the methodology cannot be fully algorithmic and may fail to either prove or disprove a given property. Model checking plays a critical role across various applications, serving purposes such as ensuring the correctness of Figure 1: A typical model-checking workflow system properties and minimizing errors in software under development.
LLM+AL: Bridging Large Language Models and Action Languages for Complex Reasoning about Actions
Large Language Models (LLMs) have made significant strides in various intelligent tasks but still struggle with complex action reasoning tasks that require systematic search. To address this limitation, we propose a method that bridges the natural language understanding capabilities of LLMs with the symbolic reasoning strengths of action languages. Our approach, termed "LLM+AL," leverages the LLM's strengths in semantic parsing and commonsense knowledge generation alongside the action language's proficiency in automated reasoning based on encoded knowledge. We compare LLM+AL against state-of-the-art LLMs, including ChatGPT-4, Claude 3 Opus, Gemini Ultra 1.0, and o1-preview, using benchmarks for complex reasoning about actions. Our findings indicate that, although all methods exhibit errors, LLM+AL, with relatively minimal human corrections, consistently leads to correct answers, whereas standalone LLMs fail to improve even with human feedback. LLM+AL also contributes to automated generation of action languages.
Two Cases of Deduction with Non-referring Descriptions
Formal reasoning with non-denoting terms, esp. non-referring descriptions such as "the King of France", is still an under-investigated area. The recent exception being a series of papers e.g. by Indrzejczak, Zawidzki and K\"rbis. The present paper offers an alternative to their approach since instead of free logic and sequent calculus, it's framed in partial type theory with natural deduction in sequent style. Using a Montague- and Tich\'y-style formalization of natural language, the paper successfully handles deduction with intensional transitives whose complements are non-referring descriptions, and derives Strawsonian rules for existential presuppositions of sentences with such descriptions.
$\texttt{FORM}$: Learning Expressive and Transferable First-Order Logic Reward Machines
Ardon, Leo, Furelos-Blanco, Daniel, Paraฤ, Roko, Russo, Alessandra
Reward machines (RMs) are an effective approach for addressing non-Markovian rewards in reinforcement learning (RL) through finite-state machines. Traditional RMs, which label edges with propositional logic formulae, inherit the limited expressivity of propositional logic. This limitation hinders the learnability and transferability of RMs since complex tasks will require numerous states and edges. To overcome these challenges, we propose First-Order Reward Machines ($\texttt{FORM}$s), which use first-order logic to label edges, resulting in more compact and transferable RMs. We introduce a novel method for $\textbf{learning}$ $\texttt{FORM}$s and a multi-agent formulation for $\textbf{exploiting}$ them and facilitate their transferability, where multiple agents collaboratively learn policies for a shared $\texttt{FORM}$. Our experimental results demonstrate the scalability of $\texttt{FORM}$s with respect to traditional RMs. Specifically, we show that $\texttt{FORM}$s can be effectively learnt for tasks where traditional RM learning approaches fail. We also show significant improvements in learning speed and task transferability thanks to the multi-agent learning framework and the abstraction provided by the first-order language.
Proof Recommendation System for the HOL4 Theorem Prover
Dekhil, Nour, Rashid, Adnan, Tahar, Sofiene
We experimented with various transformer-based language models, such as BERT [9], RoBERTa [10], and T5 [11] for these datasets to identify the most effective model based on our evaluation. After splitting the restructured datasets into a 90-10 ratio for training and testing, we proceeded to train the selected models (block highlighted in yellow) using a grid search of hyperparameters optimization. Given the multitude of possible tactics available at each proof state, we chose to provide multiple recommendations for the next proof step. To assess the accuracy of these recommendations (block highlighted in green), we use the n-correctness rate, which measures the likelihood that a correct tactic from the testing dataset is among the top-n recommended tactics, where n signifies the number of recommended tactics evaluated against the correct tactic. We found out that RoBERTa demonstrated superior performance across most cases for n = 7.
A Hybrid Deep Learning and Model-Checking Framework for Accurate Brain Tumor Detection and Validation
Fatimi, Lahcen El, Elfatimi, Elhoucine, Bouchaneb, Hanifa
Model checking is an automatic technique for verifying the correctness properties of safety-critical reactive systems. This method has been successfully applied to find subtle errors in complex systems. Model checking techniques have a wide range of application domains, among which large-scale distributed systems [1-3], signal [4], and medical images analysis [5-8]. The research related to the last topic is still ongoing looking for the perfect (precise, complete, simple) approach for analyzing medical images. The use of model checking is relatively recent, in particular regarding the verification of the analysis of medical images. In this domain, model checking in medical images has shown to be a promising application that can significantly facilitate the work of professionals. What motivates us in this study, considering that model checking is increasingly used in testing to check whether a system model satisfies a property, is to take model checking in its usual role to take on more advanced roles in medical image analysis by applying model-checking logic to medical images and detection of tumors in addition to validation of properties through tests or case studies.