1. An information processing apparatus comprising: a storage device that stores an inverted index in which documents and features of the documents are associated; and a computer configured to function as: an extraction unit that extracts features of a selected document from the inverted index; a retrieval unit that retrieves a document having any one of the extracted features; a selection unit that selects a first feature and one or more subsequent features from the extracted features; and a presentation unit that presents a combination of the features selected by the selection unit, as a retrieval condition, wherein the first feature is associated with the least number of the documents among the extracted features, and each subsequent feature (i) is associated with the least number of the documents having all of the previously selected features among the extracted features, or (ii) is a feature of which an angle with a previously selected feature vector is closest to the orthogonal among the extracted features.