Grep Without Word Boundaries: 70 Tokens Across 7.68M Words, and os Is Real 0.1% of the Time

Sources

· OpenAI, "GPT-4 Technical Report," arXiv:2303.08774, Appendix C ("Contamination on professional and academic exams") — contamination methodology and its stated limitations, quoted verbatim from the report.

· Liu, Z., et al., "HERALD: Counterfactual Audits and Minimal Repairs for Proof-of-Retrieval Rewards," arXiv:2608.06012 (submitted August 6, 2026) — abstract quoted verbatim; the citation-laundering finding and repair.

· Corpus statistics and token measurements are from our own knowledge-base scan of August 9, 2026 (2,011 files; 7,683,956 words), reproducible with the measurement script described above; carrier examples are quoted from that corpus.