Hello Jürgen, The apl.html doc indicates that if environment variable APL_LIB_ROOT is not defined, the subject search path will be from the current directory '.' up to the root directory '/' stopping when a directory containing two directories ’workspaces’ and ’wslib1’ is found.
The above does not work on my platform, Fedora 25. For instance, 'plotsincos.xml' is in ../workspaces relative the current directory. )lib plotsincos yields IMPROPER LIBRARY REFERENCE 'plotsincos': No such file or directory and )lib 0 plotsincos yields IMPROPER LIBRARY REFERENCE '0': No such file or directory. Is this a bug or has the feature been removed and the documentation is out of date. A related question is if the feature were to work correctly, would the )libs command use the feature so its output reflects the location of the library directory paths that will be used by the )lib command. Currently, it does not. Regards, Fred