Some Terms

To simplify this paper, some terms are explicitly defined. A ``statement'' refers to an individual line of Tcl code, including all arguments. The first argument is called the ``command''; all subsequent whitespace-separated arguments are called ``arguments'' or ``args''. If a command was not defined by proc, but exists in the interpreter (eg. it is a registered C callback function), it is called a ``builtin''. Note that the entire Tcl core command set is implemented as builtins.