An inductor pump system comprises a fluid activated ram, an inductor pump platen, a fluid activated motor and a fluid control. According to the method and apparatus, the primary depth checking is performed before the performing of the texture mapping, and thus the unnecessary performing of the texture mapping can be removed. For each pair of words occurring in the document set, their respective fuzzy sets are used to calculate the probability that the first word of a pair is semantically suitable as a replacement for the second word of the pair, these probabilities being collated to form a word similarity matrix for use in an improved method of determining document similarity and in information retrieval. Each pad contains markings along its width to enable the runner to place his feet at precisely the desired width.