In Duffie v. United States, 600 F.3d 362 , 367 (5th Cir. 2010), though ultimately determining that the adjustments at issue in that case were computational, this court first determined whether the Tax Courts tax-motivated transaction determination was sufficient as a matter of law. Duffie, 600 F.3d at 378-80, 383. The Duffie court found that the tax-motivated transaction determination did not require a finding that an individual partner lacked a profit motive when engaging in the relevant transaction, and thus rejected the taxpayers argument that the tax- motivated transaction determination was insufficient. See Duffie, 600 F.3d at 378. After making that determination, the only issue was whether the underpayment attributable to tax-motivated transactions was substantial, i.e. whether it was over $1,000; clearly a computational rather than a substantive issue. 600 F.3d at 386.