Use one named, certified norm on a fixed real coordinate space: l1(v)=sum_i |v_i| or linfinity(v)=max_i |v_i|. Set d(x,y)=norm(x−y) on that same space. Its universal norm-axiom certificate establishes the metric axioms; finite distance samples do not. Do not infer that every metric comes from a norm, or claim completeness, compactness or an inner product. norm_name=l1, dimension=1, evidence_mode=finite_samples. Give (norm_name,dimension,evidence_mode,sufficient?,boundary). named_formula_certificate yields universal_from_norm_axioms; finite_samples yields samples_do_not_establish_induced_metric.
G001 — Use one named, certified norm on a fixed real coordinate space: l1(v)=sum_i |v_i| or linfinity(v)=max_i |v_i|. Set d(x,y)=norm(x−y) on that same space. Its universal norm-axiom certificate establishes the metric axioms; finite distance samples do not. Do not infer that every metric comes from a norm, or claim completeness, compactness or an inner product. norm_name=l1, dimension=1, evidence_mode=finite_samples. Give (norm_name,dimension,evidence_mode,sufficient?,boundary). named_formula_certificate yields universal_from_norm_axioms; finite_samples yields samples_do_not_establish_induced_metric.
Definition and scope
Use the original question domain, assumptions and cited MKO definitions. This item has second-context mathematical and bilingual review, with the model, answer and every arithmetic step independently recomputed from the original parameters; the source question remains a candidate.
evidence sufficient=No;sample failure does not deny named formula metricity
Conditions: none
A universal named-norm certificate suffices;finite distance samples do not cover all points of the metric axioms.No judges the evidence insufficient,not the known named formula nonmetric.
S001 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
Result
(l1, 1, finite_samples, No, samples_do_not_establish_induced_metric)
The full substitutions and premise checks give the original answer; source identity,format and status are unchanged.
This question review and source binding
Review date: 2026-10-26
Original questions, answers, step expressions, numeric ASTs and historical records are retained. Source candidate labels remain historical and are not overwritten as formal proof.