What do you mean by "superposed"? Do you mean that Entry is descended from Dictionary (or vice-versa)? Is that necessary or desired?

What you're describing, though, as other posters mentioned, is perfectly fine from a design point of view.

package Dictionary;
...
sub check {
   my $self = shift;
   my $error;
   foreach (@{$self->{children}}) {
      $error++, last unless $_->check(@_)
   }
   return !$error;
}

package Entry;
...
sub check {
   my $self = shift;
   return 1 if $self->{value} > 0;  # or whatever
   return;
}
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If one is a descendent of the other, though, that makes things a little weirder but still workable.