# EP 2157931 B1 revision history

Append-only Arc G field-change log. Forward-only honesty: events accrue from Arc G adoption.

Patent: [EP 2157931 B1](/patents/ep2157931-rosa-neurosurgery.md)

## Recorded posture

- First recorded event: 2011-02-23
- Last material change: 2011-02-23
- Material event count: 1
- Editorial event count: 0

## Material events (1)

- **2011-02-23**: created (source: https://patents.google.com/patent/EP2157931B1/en) (verified)

## Forward-only note

Arc G is forward-only. The event log accrues from the Arc G adoption point. Fields with no events post-baseline equal the current cached value and are not independently verified at any prior date.

_Canonical URL: /patents/ep2157931-rosa-neurosurgery/history. HTML: [/patents/ep2157931-rosa-neurosurgery/history](/patents/ep2157931-rosa-neurosurgery/history)._