#....
    my @accum;
    foreach  my $int (@intervals )
    {
       if (num_of_tupl($int) >= 4)
       {
          print Dumper $int;   # It prints correctly in this line
          push @accum,$int;
       }
    }    
    print "ACCUM: ";
    print Dumper \@accum ;  # Problem here