Saijiki is classified by the five seasons; the new year, spring, summer, autumn and winter. The each season is further classified by the three small seasons; early, middle and late season. Under the small seasons the glossary of seasonal words are arranged by the classification, such as plants, animal, foods, folklore and so on.
The reader read the most concerned words freely and easily. at that place word's seasonal meaning and illustrative Haiku are describing. This example Haiku is so interesting and sometimes fantastic, because one can fly the different season, time and folklore by one's interest.
So recently I realised that I can read mathematical books alike Saijiki.
Many theorems, corollaries and lemmas are alike the glossary of the saijiki. I read them freely and adopt one of them for my study just as one seasonal word is adopted for the composition of Haiku at that time.
