The command tt(RENAMEMACRO) takes two arguments: the name of a built-in macro
(such as tt(INCLUDEFILE)) and its new name.

E.g., after

verb(RENAMEMACRO(INCLUDEFILE)(include))

a file must be included by tt(include(file)), and no longer using
tt(INCLUDEFILE). 

Note that following the tt(RENAMEMACRO) action, the old name can no longer 
be used; it is then an unknown symbol.

If you want to make an em(alias) for a built-in command, do it with 
tt(DEFINEMACRO). E.g., after:

verb(\
DEFINEMACRO(include)(1)(INCLUDEFILE(ARG1)))

both tt(INCLUDEFILE) and tt(include) can be used to read in a file.
