The commands for adding and deleting list members are: concat ?arg1 arg2 ... argn?
Concatenates the args into a single list. It also eliminates leading and trailing spaces in the args and adds a single separator space between args.
The args to concat may be either individual elements, or lists. If an arg is already a list, the contents of that list is concatenated with the other args. lappend listName ?
arg1 arg2 ... argn? Appends the args to the list listName treating each arg as a list element....
