Answer
You can only save an IAL's definition to a file at the point you first create it, from the IAL Object Developer window in IEE — there's no way to export an existing IAL's definition after the fact. If you don't have that original saved file, you'll need to inspect the IAL's actual database objects directly instead: creating an IAL generates the relevant views and tables under the IAL owner schema (typically IFSINFO), so querying the database catalog for objects under that schema lets you see what the current definition actually looks like, even without an exportable file.