A specification for the Eli system is made up of a number of files written in different languages. Each language is designed for a specific problem class, and is intended to reflect the ``natural'' way in which problems in that class are described by humans. The disadvantage of this approach is that a person wishing to use Eli must learn more than one language; the advantage is that specifications are more easily written and understood.
This section gathers together the components of the Eli specification for the straight-line program interpreter, combining them into files of the appropriate types.