 An argument-text schema is a schema whose instances are argument-texts. An argument-text is a two part system composed of a set of sentences called the premises and a single sentence called the conclusion. (An argument is that which is expressed by an argument-text, as a proposition is that which is expressed by a sentence.) Of the various ways of presenting an argument-text perhaps the one least open to misinterpretation is the premises-line-conclusion format which consists in listing the premises followed by a line followed by the conclusion. For example: