C.40.CD:5.1 - A mixed transfer leaves a narrower comparison available

An investigation requires each error/non-error comparison to share both setup and temperature regime. An existing grouping operation uses setup alone. The permitted target records are:

The source operation returns T1–T2 and T3–T4. Comparing those outputs with the target rule exposes the first pair’s temperature mismatch.

The changed local problem is to return eligible pairs and expose where no comparison is supported. An available filtering operation adds temperature to the grouping key. It returns T3–T4 and no eligible S1 pair. This operation constructs the target comparison; repeating the old setup-only grouping would preserve the mismatch.

The result permits the S2/warm comparison if it serves the investigation. The S1 question remains open. A next inquiry can seek a comparable S1 record when obtaining it could change the needed explanation; alternatively, receiving work can use the narrower result or stop. The original source operation retains its uses where setup alone was the applicable rule.

The grouping has established eligibility for comparison. A causal explanation would need the separate reasoning and observations for that claim.