Modeling the Diachronic Evolution of Legal Norms: An LRMoo-Based, Component-Level, Event-Centric Approach to Legal Knowledge Graphs
Hudson de Martim
TL;DR
This paper addresses the need for deterministic, auditable representations of how legal norms evolve over time, enabling exact reconstruction of texts as they stood on any date. It introduces a structured diachronic pattern based on the IFLA $LRMoo$ ontology, using a two-tier model with $TV$ (Temporal Version) and $LV$ (Language Version) realized by $F1$ Works and $F2$ Expressions, extended to Components via parallel hierarchies and $F27$ Work Creation events. The Brazilian Constitution case study demonstrates how the approach traces amendments from macro-level instruments to micro-level textual changes, linking each state to its provenance. The work provides a semantically rich backbone for Legal Knowledge Graphs, supporting deterministic reasoning and trustworthy AI in high-stakes legal contexts. Future directions include a full OWL ontology, scalable knowledge-graph population tooling, and benchmarks for formal, deterministic reconstruction.
Abstract
Representing the temporal evolution of legal norms is a critical challenge for automated processing. While foundational frameworks exist, they lack a formal pattern for granular, component-level versioning, hindering the deterministic point-in-time reconstruction of legal texts required by reliable AI applications. This paper proposes a structured, temporal modeling pattern grounded in the LRMoo ontology. Our approach models a norm's evolution as a diachronic chain of versioned F1 Works, distinguishing between language-agnostic Temporal Versions (TV)-each being a distinct Work-and their monolingual Language Versions (LV), modeled as F2 Expressions. The legislative amendment process is formalized through event-centric modeling, allowing changes to be traced precisely. Using the Brazilian Constitution as a case study, we demonstrate that our architecture enables the exact reconstruction of any part of a legal text as it existed on a specific date. This provides a verifiable semantic backbone for legal knowledge graphs, offering a deterministic foundation for trustworthy legal AI.
