This section describes the complete set of specifications used to generate a solution to Appel's interpreter problem. It is a single FunnelWeb file from which the Eli system can generate either the executable solution or the set of specification files.
Section 3.1 specifies the abstract syntax tree for the language without reference to any particular computation. The material there is simply transliterated from Appel's book. Computations to carry out the interpretation are attached to appropriate nodes in Section 3.2. An abstract data type is defined in Section 3.3 to map identifiers to the integer values assigned to them. Finally, Section 3.4 describes the initialization code and Section 3.5 produces the specification files.