Experience with Omega. Implementation of a Prototype Programming Environment, Part 4

This is the fourth report of a series exploring the use of the Omega programming notation to prototype a programming environment. This environment includes an interpreter, unparser, syntax directed editor, command interpreter, debugger and code generator, and supports programming in a small applicative language. The present report extends the interpreter, unparser, syntax directed editor, command interpreter and debugger to accommodate recursive function definition and invocation, and completes the extension of the language into an applicative programming system supporting higher-order functions. An implementation of these ideas is listed in the appendices.