authority in a resentenc-ing proceeding under § 3582(c)(2) is a question of law that we review de novo.” United States v. Rhodes, 549 F.3d 833, 837 (10th Cir.2008). The government contends that Mr. Mata-Rodriguez is only entitled to plain-error review because he did not first raise his appellate arguments before the district court. However, we need not reach a conclusion on this matter, because even under the standard of review that is more favorable to Mr. Mata-Rodriguez (i.e., abuse of discretion), he cannot prevail. Mr. Mata-Rodriguez’s arguments depend on the contours of the sentence-modification procedure set out in 18 U.S.C. § 3582(c)(2). That procedure is limited and our caselaw has articulated its contours. See United States v. Washington, 759 F.3d 1175, 1181 (10th Cir.2014) (<HOLDING>). The district court, within its discretion,
recognizing that the modification procedure set out in  3582c2 is carefully constrained holding that when an agency fails to follow the proper procedure under the illinois administrative procedure act for the adoption of rules the rule is invalid holding that a bid award may be set aside if either 1 the procurement officials decision lacked a rational basis or 2 the procurement procedure involved a violation of regulation or procedure holding that an ineffective grievance procedure bars employers defense based on that procedure recognizing that the simple and expeditious motion procedure set forth in fed rapp p 24a5 rather than an appeal from  the certification of lack of good faith is the proper procedure for calling in question the correctness of the action of the district court