#!perl
use warnings;
use strict;

use Algorithm::Loops 'NestedLoops';
my @symbol = (
   [ 'a', 'b', 'c' ],
   [ 'a', 'b', 'c'  ],
   [ 'a', 'b', 'c'  ],
   [ 'c', 'd', 'e'  ],
);

my $combos = NestedLoops([
  $symbol[0],
  map {
    my $_hold = $_;
    sub {
      [grep {$_ ge $_[$#_]} @{$symbol[$_hold]}]
    }
  } 1..$#symbol
]);

my @result;
print "@result\n" while @result = $combos->();