name: synth-rule-claims
description: Which synth rules pre-claim a field ahead of its linear model, conditional pairs and residual correlations, the four exclusions that are silent if got backwards, and why the fidelity report is the reason.
type: guide
kind: design
applies_to: inspect, predict, manifest
covers: [synth, rules, conflicts, models, pre-claim]
requires: [capability:synth]
Synth rule claims
What a rule retires
A rule that DETERMINES a field pre-claims it at priority 0 in resolveConflicts, ahead of the linear-model pre-claim — the rule pass runs last and an unconditional write wins outright, so nothing upstream should produce a value it discards. Three things stop for that field: its models entry, any conditional pair naming it, its place in residual_correlations. Each loss is warned in the ordinary wording (conditional relationship conflict: field "promoter" is already claimed by structural rule 0 (set_expr); dropping linear model).
A whole-field claim SUBSUMES that field’s set_* OPTIONS, so an unconditional rule writing a whole multi-select retires the per-option set-set / set-categorical pairs driving it. One-directional: an option-level claim does NOT reach the whole field, since a pair driving one option has said nothing about the others.
The report is the reason, not the wasted work. FidelityReport.Models asks generation’s own compiler which models ran, so without the claim a rule-overwritten modelled field ships a captured-versus-recovered coefficient delta for a value nothing kept — every number rendering, nothing saying it describes something that did not happen.
Four exclusions, each SILENT if got backwards:
| Rule shape | Claims? | Why |
|---|---|---|
set / set_expr, no when | yes | writes every row from inputs the field’s own generation does not supply |
carries a when | no | writes only some rows; claiming strips the model from the rest, leaving a plausible bare marginal |
set_null (any conditionality), owns_nulls or not | no | removes a value rather than supplying one — if gate then null else inferred needs the model to produce what non-gated rows keep. Ownership suppresses the NULL DRAW and claims nothing; the value is still the model’s |
null_together | no | copies one null decision; supplies no value |
set_expr reading its OWN target | no | transforms what generation produced rather than determining it |
The last is why the pre-rounding remedy {"set_expr": {"nps": "round(nps)"}} is safe: claiming there would leave the rounding applied to a bare marginal draw — the documented fix for one silent fault causing a larger one. Self-reference is detected on the PARSED expression, never by substring (nps_reason is not nps), and an unparseable expression answers “reads”, the direction that cannot lose structure.
One contract narrows. The pass still consumes no RNG, but a CLAIMING rule retires a model and a retired model stops drawing its own per-row normal, so the stream shifts — for a reason a warning names. No rules, or rules claiming nothing ⇒ byte-identical.
See
synth-conflicts— the full claim order;synth-models·synth-model-recovery.synth-rule-expressions— the pre-rounding remedy that must not claim.