Attempting to access external information about an internal function.
#2041 Compile-time error
Attempting to access external information about an internal function.
Additional Information
For function 'X', for operator 'Y'.
where Y is either FUNCTION-LIBRARY or EXTERNAL-FUNCTION (the name by
which function X is known in the library).
Explanation
Internal functions do not have information related to FUNCTION-LIBRARY
or EXTERNAL-FUNCTION.