for my $nnot ( map { $solution[-1] + $_, $solution[-1] - $_ }
                   nmap { $_ if ($availableIntervals[$_] > 0) }
                        (1 .. 11)
              ) {

##</code><code>##

sub nmap(&@){
   my $rout = shift; # get mapping routine
   my @list = ();    # output list
   my $curr;         # current result
   for (@_) {
      $curr = $rout->($_); # get result
      if (defined $curr) {  # if $curr is defined
         push @list, $curr; # add it to the list
      }
   }
   return @list;
}