An example to [namespace children] command :
======
        puts [info patchlevel]
        # Tcl
        set tclVersion [package require Tcl]        
        puts "Tcl ($tclVersion)"
        puts [lsort [namespace children]]
        set tkVersion [package require Tk]
        # Tk
        puts "Tk ($tkVersion)"
        puts [lsort [namespace children]]
        exit


        $ tclsh namespaces.tcl
        8.4.17
        Tcl (8.4)
        ::activestate ::platform ::tcl
        Tk (8.4)
        ::activestate ::auto_mkindex_parser ::critcl ::dom ::msgcat ::pkg ::platform ::tcl ::tk ::vfs ::xml

        $ tclsh85 namespaces.tcl
        8.5.7
        Tcl (8.5.7)
        ::activestate ::platform ::tcl
        Tk (8.5.7)
        ::activestate ::auto_mkindex_parser ::msgcat ::pkg ::platform ::tcl ::tk ::ttk
======

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