D129 - Two progress signals

Status: decided Date: 2026-09-26

A run is compared with the previous run of the same title on two signals - distinct imports reached and the fault position - and the verdict names which moved: FURTHER, same, BACK, or MIXED with the reason. The shader corpus reports movement in the same vocabulary.

Why: a fault position compares two points on one path and says nothing across two paths, so alone it calls real progress backwards. Distinct imports survives a change of path. Unattended work steers by this verdict, and a misleading one is worse than none.

Rejected:

• Fault position alone: wrong the moment the path changes.
• Import count alone: inflatable, and blind to progress within a path.
• A separate vocabulary for shaders: two words for one loop.