PRCPrimeCalibrationForcesNonunitNoMixedWitnessesTarget_of_identity_witness_excludes
plain-language theorem explainer
Under prime-direction calibration of a ratio character, the one-sided identity-witness exclusion hypothesis implies the existential no-mixed-witnesses target: identity-oriented and reciprocal-oriented nonunit witnesses cannot coexist. Anyone tracking the PRC native-cost uniqueness blocker chain cites this bridge. The proof is a one-line specialization that feeds the character-level exclusion lemma.
Claim. Assume that every prime-direction-calibrated ratio character $\chi$ has the property that any identity-oriented nonunit witness is incompatible with every reciprocal-oriented nonunit witness. Then every such $\chi$ also forbids the coexistence of any identity-oriented nonunit witness with any reciprocal-oriented nonunit witness.
background
In the Primitive Recognition Calculus, a ratio character $\chi$ is a map on ratio orbits that encodes how recognition cost transforms under multiplicative structure. Prime-direction calibration fixes the orientation of $\chi$ along prime generators so that local sign/orientation choices cannot freely flip when witnesses are globalized.
Two witness-side targets appear here. The one-sided exclusion target asserts that, once $\chi$ is a ratio character and prime-calibrated, any identity-oriented nonunit witness rules out every reciprocal-oriented nonunit witness. The existential no-mixed-witnesses target is weaker in surface form: it only forbids simultaneous existence of one identity-oriented and one reciprocal-oriented nonunit witness. Both are quantified over all such calibrated characters.
Upstream, the character-level lemma already shows that identity-witness exclusion implies no mixed witnesses for a fixed $\chi$. This declaration lifts that implication to the quantified prime-calibration targets used by the native-cost uniqueness certificate stack.
proof idea
Term-mode specialization, not a new argument. Introduce an arbitrary ratio character $\chi$ together with the hypotheses that it is a ratio character and prime-direction calibrated. Apply the assumed target hypothesis to obtain identity-witness exclusion for that $\chi$. Then invoke the character-level theorem that identity-witness exclusion implies no mixed witnesses, and discharge the goal. No extra algebraic identities or case splits appear.
why it matters
This is one direction of the equivalence between the one-sided exclusion target and the existential no-mixed-witnesses target under prime calibration. The sibling iff theorem packages both directions; the native-cost uniqueness blocker certificate and the universal-foundation conditional certificate sit downstream of that witness-split infrastructure.
In the Recognition framework the point is orientation hygiene: prime calibration is meant to strip local orientation out of witness globalization so that cost uniqueness cannot be spoiled by mixed identity/reciprocal nonunit witnesses. That hygiene feeds the PRC path toward a unique native cost functional, which is the foundation-layer counterpart of J-uniqueness (T5) and the Recognition Composition Law. The declaration itself is a proved bridge, not an open scaffold; it closes the target-level implication once the character-level exclusion lemma is in hand.
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