Structured Arguments.
The modern editor for high-assurance engineering. Build, validate, and share assurance cases with confidence.
The tools haven't kept up
Assurance cases are critical documents — they argue why systems are safe to operate, secure to deploy, ethical to release. But the tools haven't kept up.
- Desktop-only editors like ASCE and NOR-STA with no real-time collaboration
- Manual file merging between team members
- No structural validation until review time
- Interfaces designed for a previous decade
Assurance argumentation, in the browser
Lemmatica brings assurance argumentation into the browser.
- Real-time collaboration with live cursors and presence
- Automatic GSN V3 structural validation as you build
- Dialectic extensions for rigorous challenge and response
- Built for teams, not individuals
Everything you need for high-assurance arguments.
Replace scattered Visio files and documents with a single source of truth.
Real-time Collaboration
Multiplayer by default. See colleagues cursors, comments, and edits as they happen.
GSN V3 Compliance
Full support for standard and extended GSN notations. Always continuously verified.
Live Validation
Catch structural errors instantly. Undeveloped goals are flagged before you commit.
Dialectic Support
Capture counter-arguments and defeaters. Visually track argument resilience.
Branch & Merge
Propose changes in isolation. Review diffs visually before merging to main.
From draft to done in three steps
Build your argument
Draft goals, strategies, and evidence on a spatial canvas with automatic hierarchical layout.
Validate as you go
Lemmatica checks GSN V3 structural rules continuously and flags incomplete arguments.
Collaborate in real time
Share a link. Your team sees every change instantly. No file merging. No version conflicts.
Ready to modernise your assurance cases?
Join high-assurance teams building with confidence. Free during beta.