appeal pro se the Tax Court’s decision, following a bench trial, in favor of the Commissioner in their action contesting tax deficiencies for the years 1988 through 1997. We have jurisdiction pursuant to 26 U.S.C. § 7482. We review de novo a Tax Court’s conclusions of law. See Boyd Gaming Corp. v. Comm’r, 177 F.3d 1096, 1098 (9th Cir. 1999). We affirm. The Tax Court properly sustained the deficiency determination based on Forms 4340 for the years in question. See Hughes v. United States, 953 F.2d 531, 535-36 (9th Cir.1992). Contrary to petitioners’ contention, the IRS officer is not required to provide them with documentary evidence and copies of statutory notices verifying that all procedural steps were properly taken. See Hansen v. United States, 1 F.3d 137,138 (9th Cir.1993) (<HOLDING>). The Tax Court properly held that petitioners
holding that form 4340 is probative evidence in and of itself and shows in the absence of contrary evidence that notices and assessments were properly made holding that form 4340 showing notice of assessment and demand for payment is admissible under the federal rules of evidence holding that the trial court properly excluded evidence relating to a purported additional suspect where the evidence was speculative and had little or no probative value holding that official certificates such as forms 4340 can constitute proof of the fact that the assessments were actually and properly made holding that a statutory presumption is a rule of law requiring a trier of fact to reach a particular conclusion in the absence of evidence to the contrary