pdl-perl-square-matrix

# Script p.pl
use feature qw(say);
use strict;
use warnings;
use PDL;
my $m = pdl [[0,0,1,0],[0,0,1,0],[1,1,0,1],[0,0,1,0]];
my $m2 = $m x $m;
print $m2;

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Output:
$ perl p.pl
[
 [1 1 0 1]
 [1 1 0 1]
 [0 0 3 0]
 [1 1 0 1]
]