max is available as a function in [expr] or as a command in Tcl 8.5. Given a variable number of numeric arguments, it returns the one that is numerically largest. % expr max(2,3,4,5,6,-99) 6 % namespace import ::tcl::mathfunc::max % max 2 3 4 5 6 -99 6 This does not work in releases up to 8.5.4 because max and min are not importable. This should be fixed in subsequent versions. [RS] 2008-09-19: Before that, you can hot-patch it yourself in one line of code: namespace eval tcl::mathfunc namespace export max min ;# this is it namespace import tcl::mathfunc::max If you are working with Tcl releases older than 8.5, it is not difficult to create procedures that provide the same capability. Various ways: in a loop (works for numeric and string values): proc max list { set res [lindex $list 0] foreach element [lrange $list 1 end] { if {$element > $res} {set res $element} } set res } By sorting (this is for numeric values only): proc max list {lindex [lsort -real $list] end} ---- See also [Reinhard Max] ---- !!!!!! %|[Category Function]|[Category Mathematics]|% !!!!!!