Recently on comp.lang.tcl, Tom Wilkason wrote: "... Incidentally, for backwards compatibility you can have lset for older tcl versions with the following code run during script processing:"
proc K {a b} {set a}
if {[string equal [info command lset] {}]} {
proc lset {listName index val} {
upvar $listName list
set list [lreplace [K $list [set list {}]] $index $index $val]
}
} ;# end if