% Return non-zero if any entries in @var{x} are duplicates of one
SYNOPSIS
function retval = is_duplicate_entry (x)
DESCRIPTION
% -*- texinfo -*-
% @deftypefn {Function File} {} is_duplicate_entry (@var{x})
% Return non-zero if any entries in @var{x} are duplicates of one
% another.
% @end deftypefn
