RosettaCodeData/Task/List-comprehensions/Perl-6/list-comprehensions.pl6

my $n = 20;
gather for 1..$n -> $x {
         for $x..$n -> $y {
           for $y..$n -> $z {
             take $x,$y,$z if $x*$x + $y*$y == $z*$z;
           }
         }
       }