In Rachmaninoff's Rhapsody On A Theme Of Paganini, he uses both L'istesso Tempo (same tempo) and Tempo Precedente (previous tempo) for different variations (see image of structure). What is the difference between these 2 and why would both be used in the context of this work? I cannot find the answer to this in any analysis.
Also, would I be I right in saying that "Precedente", below Var. 1 in this image, means the variation that precedes the main theme?