From Tcl 8.5, list non-inclusion expr operator. E.g.
if {$el ni $list} ...
Opposite of in. - rs 2007-04-26
set el Mon set list [list Mon Tue Wed Thu Fri Sat Sun] if {$el ni $list} { puts "Inalid day abbreviation" } else { puts "Vvalid day abbreviation" }
Category Command a subcommand of expr