# AI claims can recite math and still pass § 101. In September 2025 the Office’s Appeals Review Panel vacated a § 101 rejection of a DeepMind machine-learning claim, and the decision became precedential in November. The claim recited math. It was eligible because it reflected an improvement to how the model itself works. The applicant still faced an obviousness rejection. Sources checked October 16, 2026 **Won § 101** and still rejected as obvious. The decision did not produce a patent. ## Before you read A claim recites a mathematical calculation for training a model. Under Desjardins, is it ineligible for that reason? - Yes: math is an abstract idea - Not necessarily: it can be eligible if the claim reflects an improvement to how the model works - Only if it is also novel Not necessarily. Claim 1 recited math, but the claim as a whole reflected an improvement to the model’s operation, so it was “not directed to an abstract idea.” ## The new ground A Board panel had affirmed an obviousness rejection of a DeepMind application on training machine-learning models. Then, on its own initiative, it entered a new rejection: the claims were ineligible abstract ideas under § 101. An Appeals Review Panel led by the Director was convened to review that step. It vacated the new ground, calling the reasoning “overbroad” and “troubling.” Desjardins, pp. 2–10 ## The claim and the test Claim 1 covers a computer-implemented method for training a model that already learned one task to learn a second, different task while protecting performance on the first. It does this by weighting how important each parameter was to the first task. Eligibility runs through the Supreme Court’s Alice framework: laws of nature, natural phenomena and abstract ideas are not patentable. The Office applies it in steps. Desjardins ## The improvement, in the claim A statement in the specification isn’t enough on its own; the claim has to reflect the improvement. Here it did. The specification described a model that can learn new tasks in succession while protecting what it learned before, using less storage because one set of parameters serves several tasks. The claim’s limitation carried that through. Desjardins The holding: “although independent claim 1 may recite an abstract idea, it is not directed to an abstract idea.” The same analysis covered claims 18 and 19 and every dependent claim. Desjardins ## The message to examiners The panel criticized reasoning that treats any machine learning as an unpatentable algorithm and the rest as generic computer parts: “Examiners and panels should not evaluate claims at such a high level of generality.” It also said where the real limits are. Desjardins The claims still stood rejected as obvious. The applicant won the eligibility issue without getting a patent from this decision. ## Where Desjardins sits Desjardins is one of two precedential § 101 decisions in ex parte appeals on the USPTO list, with Mewherter (2013). USPTO list ## What to do Choose your side. ## Cuts the other way Desjardins binds the Office within its scope, not the courts. A claim the Office finds eligible can still be held ineligible in litigation, and a court’s § 101 ruling can end a pending IPR, as it did in Hulu v. Piranha. Hulu v. Piranha An IPR can’t hear § 101 at all. 35 U.S.C. § 311(b) ## The takeaway Report the eligibility win, then the next obstacle between the client and useful claims. ## Related stories - [Win § 101 in court, and the IPR ends.](https://postgrantproceeding.com/insights/d07-win-101-in-court) - [Expires first, still rejected.](https://postgrantproceeding.com/insights/d17-expires-first-still-rejected) - [The precedent in your template may have retired.](https://postgrantproceeding.com/insights/d20-the-precedent-in-your-template-may-have-retired) ## Sources - S34. Ex parte Desjardins, Appeal No. 2024-000567 (USPTO Appeals Review Panel September 26, 2025) (precedential, designated Nov. 4, 2025). https://www.uspto.gov/sites/default/files/documents/202400567Ex_parte_Desjardins_arp_rehearing_decision.pdf - S88. USPTO, Precedential and informative decisions (PTAB), as checked Oct. 16, 2026, and PostGrantProceeding's inventory of the list (341 entries, Oct. 2026). https://www.uspto.gov/patents/ptab/precedential-informative-decisions - S46. Hulu, LLC v. Piranha Media Distribution, LLC, No. IPR2024-01252, Paper 27 (USPTO Acting Director Apr. 17, 2025) (informative, designated May 7, 2025), also covering IPR2024-01253. https://www.uspto.gov/patents/ptab/precedential-informative-decisions - S13. Federal patent statutes, 35 U.S.C. §§ 253(a), 303(a), 311–315, 317 and 321–325. Reproduced in MPEP Appendix L (currency date stated by the appendix: Jan. 31, 2024). https://www.uspto.gov/web/offices/pac/mpep/mpep-9015-appx-l.html Precedential decisions bind the Board within their designated scope. Informative decisions show the Office’s reasoning but do not bind the Board. Court opinions are cited for what they decided; later history was checked on the date shown above. General information about published decisions, not legal advice. Reading it does not create an attorney-client relationship.