Steven Reid
Independent Researcher
ORCID: 0009-0003-9132-3410
sreid1118@gmail.com
April 2026
This paper formalizes a branch-limited quantitative layer for the OCP anti-classifier program. On finite witness classes with binary exactness verdicts, we define descriptor fibers and prove two finite-class results: a purity criterion for perfect descriptor-only classification and an irreducible descriptor-only error lower bound. We then define computable invariants: descriptor-fiber mixedness (DFMI), irreducible descriptor error lower bound (IDELB), and compatibility lift (CL). On current OCP witness artifacts, amount-only descriptors are mixed (DFMI=1) with nonzero irreducible error, while adding compatibility information collapses the lower bound to zero on the tested rank witness class. Scope is intentionally restricted to supported finite witness families.
Keywords: anti-classifier, descriptor fibers, recoverability, incompatibility, finite witness classes, branch-limited invariants
This branch is a quantitative extraction layer under the restricted-linear and fiber no-go program. It is not a universal theory and is not a replacement for core projector/recoverability branches.
Let W be a finite witness set with exactness verdict v: W -> {0,1} and descriptor map a: W -> A.
For each descriptor value alpha in im(a), define:
E_alpha = |{w in W : a(w)=alpha, v(w)=1}|F_alpha = |{w in W : a(w)=alpha, v(w)=0}|The preimage a^{-1}(alpha) is a descriptor fiber.
A perfect deterministic descriptor-only classifier h: A -> {0,1} satisfying h(a(w))=v(w) for all w in W exists iff every descriptor fiber is verdict-pure:
alpha, either E_alpha=0 or F_alpha=0.Necessity: if h is exact, all witnesses with same descriptor must share a label.
Sufficiency: if every fiber is pure, assign the unique fiber label to h(alpha).
Define:
IDELB(a;W) = (sum_alpha min(E_alpha,F_alpha))/|W|For any deterministic descriptor-only classifier h: A -> {0,1}:
Err_W(h) >= IDELB(a;W).Majority vote on each fiber attains this bound.
If any descriptor fiber is mixed (E_alpha>0 and F_alpha>0), perfect descriptor-only classification is impossible on W.
Define:
DFMI(a;W) = |{alpha : E_alpha>0 and F_alpha>0}| / |im(a)|CL(b|a;W) = IDELB(a;W) - IDELB((a,b);W)CL measures reduction in irreducible descriptor-only error after adding compatibility descriptor b.
Computed from:
data/generated/unified-recoverability/rank_only_classifier_witnesses.csvdata/generated/unified-recoverability/candidate_library_budget_witnesses.csvSummaries:
data/generated/descriptor-fiber-anti-classifier/meta_classifier_invariants.csvdata/generated/descriptor-fiber-anti-classifier/meta_classifier_invariants.jsonObserved on current witness suites:
DFMI=1.0, IDELB=0.5.DFMI=1.0, IDELB≈0.2857.IDELB=0 on tested rank witness class, giving positive CL.PROVED ON SUPPORTED FAMILY (finite witness classes).VALIDATED on generated artifacts.This paper strengthens anti-classifier diagnostics in a scoped way:
OCP-049, OCP-050, OCP-052, OCP-053;