# the next THREE are the same:
# foreach my $line (@{$ref->[3]}) { print "\t$line ${$ref->[1]}{$line}\n" }
# foreach my $line (@{$$ref[3]}) { print "\t$line ${$$ref[1]}{$line}\n" }
foreach my $line (@{$$ref[3]}) { print "\t$line $all{$$ref[0]}{$line}\n" }
}