Whether courts should apply the categorical approach to determine a controlled substance offense under USSG § 4B1.2(b) by comparing elements of prior conviction to substances controlled at time of prior conviction or time of federal sentencing, and how to interpret undefined terms 'controlled substance' and 'distribution'

1. To determine a controlled substance offense under USSG § 4B1.2(b) using the categorical approach, do courts compare the elements of the prior conviction to substances that were controlled on the date of the prior conviction , or to the substances controlled on the date of federal sentencing? 2. Does the undefined term “controlled substance ” in USSG § 4B1.2(b) take its ordinary meaning, or the statutory definition in the Controlled Substances Act, 21 U.S.C. § 80 2(6)? 3. Does the undefined term “distribution” in USSG § 4B1.2(b) take its ordinary meaning, or the statutory definition in the Controlled Substances Act, 21 U.S.C. § § 802(8) , 802(11) ?