>perl -c -we"sub outer { my $x; sub inner { $x } inner() }"
Variable "$x" will not stay shared at -e line 1.
-e syntax OK

>perl -c -we"sub outer { my $x; local *inner = sub { $x }; inner() }"
-e syntax OK

##</code><code>##

sub outer {
  ...
  my $helper;
  $helper = sub {      # $helper references helper sub
     ...
     $helper->();      # helper sub references $helper
     ...
  };
  ...
}