 [nondet]directory_member(+Directory, 
-Member, +Options)True when Member is a path inside Directory. Options 
defined are:
[nondet]directory_member(+Directory, 
-Member, +Options)True when Member is a path inside Directory. Options 
defined are:
- recursive(+Boolean)
- If true(defaultfalse), recurse into 
subdirectories
- follow_links(+Boolean)
- If true(default), follow symbolic links.
- file_type(+Type)
- See absolute_file_name/3.
- extensions(+List)
- Only return entries whose extension appears in List.
- file_errors(+Errors)
- How to handle errors. One of fail,warningorerror. 
Default iswarning. Errors notably happen if a 
directory is unreadable or a link points nowhere.
- access(+Access)
- Only return entries with Access
- matches(+GlobPattern)
- Only return files that match GlobPattern.
- exclude(+GlobPattern)
- Exclude files matching GlobPattern.
- exclude_directory(+GlobPattern)
- Do not recurse into directories matching GlobPattern.
- hidden(+Boolean)
- If true(default), also return hidden files.
This predicate is safe against cycles introduced by symbolic links to 
directories.
The idea for a non-deterministic file search predicate comes from 
Nicos Angelopoulos.