`@setfilename'
--------------

  In order to serve as the primary input file for either `makeinfo' or
TeX, a Texinfo file must contain a line that looks like this:

     @setfilename INFO-FILE-NAME

  Write the `@setfilename' command at the beginning of a line and
follow it on the same line by the Info file name.  Do not write
anything else on the line; anything on the line after the command is
considered part of the file name, including a comment.

  The `@setfilename' line specifies the name of the Info file to be
generated.  This name should be different from the name of the Texinfo
file.  There are two conventions for choosing the name: you can either
remove the `.tex' extension from the input file name, or replace it
with the `.info' extension.

  Some operating systems cannot handle long file names.  You can run
into a problem even when the file name you specify is itself short
enough.  This occurs because the Info formatters split a long Info file
into short indirect subfiles, and name them by appending `-1', `-2',
..., `-10', `-11', and so on, to the original file name.  (*Note Tag
Files and Split Files: Tag and Split Files.)  The subfile name
`texinfo.info-10', for example, is too long for some systems; so the
Info file name for this document is `texinfo' rather than
`texinfo.info'.

  The Info formatting commands ignore everything written before the
`@setfilename' line, which is why the very first line of the file (the
`\input' line) does not need to be commented out.

  The `@setfilename' line produces no output when you typeset a printed
manual, but is does an essential job: it opens the index,
cross-reference, and other auxiliary files used by Texinfo.