Libero is a code generator. It works as follows: you write a dialog description, and Libero generates (by default) C code to execute the dialog. This C code contains (a) various tables and definitions, and (b) the FSM engine. If necessary, Libero also generates (c) a skeleton C program to wrap the whole thing together. When you change your dialog (many times during program development), Libero re-generates (a) and (b) and any new bits needed in (c).

When you run the lr command, Libero goes through these steps:

It displays a start-up message and checks that it can find its message file. If this fails, there is a problem with the PATH definition.
It reads the dialog file(s) you specified.
For each dialog file, it run the language-specific schema file. The schema generates code, the exact mechanics depending on the language in question:
1. If necessary, the schema creates a skeleton program.
2. If necessary, the schema adds empty module 'stubs' to the end of the program for each module in the dialog. You will often want to rearrange these in a meaningful order.
3. The schema generates the tables and code required to run your dialog program. These go into include files or other code modules.

The standard C schema is LRSCHEMA.C. This schema creates two include files, with the dialog's name, but extensions '.D' and '.I'. The first of these contains the DATA, the second the INTERPRETER. Other schemas (for other programming languages) have different conventions.

Dialogs have the extension .l, though you can be bloody-minded and use other extensions. On systems that support long filenames, the name can be up to 128 characters long, including the extension. I seriously recommend that you stick to eight-character filenames for anything that is remotely useful. When I were a lad, filenames were one hex digit. To create a new dialog, take skeleton.l and copy it. I recommend that you give a dialog the same name as the program it drives. For instance, a source file myprog.c would use a dialog myprog.l. Sometimes I append a 'd' to the name to make the filename (without extension) unique. Then, for instance, the .bak files that my editor creates carry different names.