source files: xfil.[ch]
If the named file has already been loaded or created, nothing is done. Otherwise, this call lLoads the named file, creating all objects within it. Any files referenced by "myfile.lsp" are also loaded, if they are not already. When done loading, "myfile.lsp" will be the 'current file,' and "myfile.lsp" will have been added to the internal list of loaded files which is returned by XFIL-GET-NAMES-OF-LOADED-GRAPHICS-FILES.