inversion-require

inversion-require is a compiled Lisp function in `inversion.el'.

(inversion-require PACKAGE VERSION &optional FILE DIRECTORY &rest RESERVED)

Declare that you need PACKAGE with at least VERSION.
PACKAGE might be found in FILE. (See `require'.)
Throws an error if VERSION is incompatible with what is installed.
Optional argument DIRECTORY is a location where new versions of
this tool can be located. If there is a versioning problem and
DIRECTORY is provided, inversion will offer to download the file.
Optional argument RESERVED is saved for later use.