Firstly, Secondly, Evenly, etc.

These are meta-concepts that pick out the indicated part(s) of the subject call and apply the concept to it. "Firstly" picks out the first part of the call. It is the same as "Initially". "Secondly", "Thirdly", etc. pick out the indicated part. "Oddly" picks out the first, third, and so on. It is the same as "Random". "Evenly" picks out the second, fourth, and so on. It is the same as "Reverse Random". "Piecewise" picks out each part, and applies the concept to those parts individually. This is useful with concepts like "1/2", in which the action of applying the concept to the parts one at a time is different from that of applying the concept to the call as a whole. See the discussion of re-evaluation in Fractions and Parts.