#!/usr/bin/perl
use strict;

my @matrix;
@matrix = ( [0,1,0,0,0,0,1],
[1,0,0,0,0,0,0],
[1,1,0,1,0,0,1],
[1,1,1,0,1,0,0],
[1,1,1,1,0,1,0],
[1,1,1,1,1,0,0],
[1,1,1,1,1,1,0]
);
Kreisfrei (@matrix); # Rufe Subroutine auf
sub Kreisfrei{
my @weg=@_;
# mache irgendwas (auch in anderer Subroutine)
}