That part of a writing in which are detailed those facts which elucidate the subject. In chancery pleading, the introduction is that part of a bill which contains the names and description of the persons exhibiting the bill. In this part of the bill are also given the places of abode, title, or office, or business, and the character in which they sue, if it is in autre droit, and such other description as is required to show the jurisdiction of the court. 4 Bouv. Inst. n. 4156. The part of a writing which sets forth preliminary matter, or facts tending to explain the subject.