Non-medical structural fixture

Current state is a view, not an eraser.

An append-only history records what was observed, when a value changed, why it changed, and which version is current. Earlier material remains addressable.

Current fixture state

Two blue cards, corrected from three.

The current value and the earlier value have non-overlapping validity windows. The correction adds an event; it does not rewrite the first observation.

fixture-fact:alpha · corrected

The fictional archive contains two blue index cards.

Fixture only · unpublishable
Current value
Two blue index cards
Prior value
Three blue index cards
Source role
Primary support
Confidence
Fixture-only
Editorial status
Corrected
Last verified
Fixture timestamp

Append-only events

The change remains explainable.

  1. Observed · event 01

    Three blue cards entered.

    The first fixture value received a source reference, observed date, and starting validity time.

  2. Corrected · event 02

    Recount changed three to two.

    The first validity window closed before the corrected window began. The original event remains visible.

Different outcomes

Correction, supersession, and retraction are not synonyms.

Corrected

A material value was wrong.

A dated replacement becomes current while the earlier value and reason remain in history.

Superseded

A newer record took over.

The older record may still be accurate for its earlier validity interval.

Retracted

The record left current use.

The withdrawal and reason remain visible; the event does not become a judgment about a person.

Projection states

Silence and failure stay explicit.

No history

No events recorded

This does not mean the record never changed; only that no history is available.

Unavailable

Source cannot be checked

Current display retains its last verified date and limitation.

Invalid

Windows overlap

The projection blocks contradictory validity intervals instead of selecting one silently.

Continue exploring

Trace the source behind the event.