Introducing Lemmatica

Safety cases are critical documents. They structure the argument that a system is acceptably safe to operate — in aerospace, rail, automotive, medical devices, and increasingly in autonomous systems and AI. The notation most widely used to build them is Goal Structuring Notation (GSN), a hierarchical graph of claims, strategies, evidence, and contextual assumptions.

The tooling has not kept pace with the notation. Most teams still rely on desktop applications built a decade ago: single-user, no real-time validation, no collaboration support. Diagrams are drawn manually, exported as images, and reviewed in email threads. Structural errors — a goal with no supporting evidence, a strategy referencing a missing context — go undetected until a formal review catches them weeks later.

Lemmatica changes this.

What Lemmatica Is

Lemmatica is a web-based GSN editor purpose-built for collaborative safety case development. It implements the full GSN V3 specification, including the dialectic extensions that most tools ignore: challenge nodes, defeaters, and argument resilience tracking. It runs in the browser, requires no installation, and supports multiple users editing the same safety case simultaneously.

Core Capabilities

Real-time collaboration. Multiple engineers work on the same safety case with live cursors, presence awareness, and conflict-free editing. No more merging diagram files or waiting for someone to close a document.

Structural validation. Every edit is validated against GSN V3 rules in real time. Orphaned nodes, invalid parent-child relationships, and missing evidence are flagged immediately with inline error indicators — not discovered during review.

Dialectic extensions. Challenge nodes let reviewers raise counter-arguments directly within the safety case structure. Defeated claims are tracked explicitly, making argument resilience visible rather than implicit.

Evidence management. Solutions link to evidence with status tracking and activity logging. You can see at a glance which claims are fully supported, which are pending evidence, and which have stale references.

Hierarchical navigation. Away goals break large safety cases into manageable sub-cases with linked navigation. Complex arguments decompose naturally without losing structural traceability.

The Alpha Release

Today we are releasing Lemmatica v0.1.0. This is an alpha — the foundation is solid, but we are actively building on it. The editor, validation engine, collaboration infrastructure, and dialectic system are all functional. We are working toward evidence integration workflows, reporting, and deeper compliance tooling in upcoming releases.

If you build or review safety cases, we would like your feedback. Lemmatica is designed for practitioners, and the best way to get it right is to put it in front of the people who do this work every day.