DB<109> @a=  map { int rand 100 } 1..10
 => (96, 10, 99, 9, 43, 8, 20, 85, 42, 26)

  DB<110> sub minindex { 
             my @x=@_; 
             reduce { $x[$a] < $x[$b] ? $a : $b } 0 .. $#_ 
          }

  DB<111> print minindex @a
5