To defunctionalise:

1. Create a data constructor for each function
2. Create a data constructor for each underapplication of a function
3. Convert underapplications to their corresponding constructors
4. Create an EVAL function which calls the appropriate function for data constructors created as part of step 1
5. Create an APPLY function which adds an argument to each underapplication (or calls APPLY again for an exact application)
6. Wrap overapplications in chains of APPLY
7. Wrap unknown applications (i.e. applications of local variables) in chains of APPLY
8. Add explicit EVAL to case, primitives, and foreign calls