{
   my $var;
}
# $var no longer exists.

##</code><code>##

package main;

use strict;

$main::var = 1;
#$var = 1;              # Error!

{
   $main::var++;
   #$var++;             # Error!
   our $var;            # Disable "strict vars" for $var.
   $var++;              # Same as "$main::var++;"
}                       # "strict vars" is back on for $var.

{
   $main::var++;
   #$var++;             # Error!
   no strict 'vars';    # Disable "strict vars" for all vars.
   $var++;              # Same as "$main::var++;"
}                       # "strict vars" is back on for all vars.

print("$main::var\n");  # Prints 5.
#print("$var\n");       # Error!

##</code><code>##

$main::var = 1;

{
   local $main::var;  # Saves current value of $main::var
                      # and sets new value to undef.
   
   $main::var = 2;
} # Restores saved value of $main::var.

print("$main::var\n");  # Prints 1.

##</code><code>##

package main;

our $var;
$var = 1;

{
   local $var;        # Saves current value of $main::var
                      # and sets new value to undef.
  
   $var = 2;
} # Restores saved value of $main::var.

print("$var\n");      # Prints 1.

##</code><code>##

sub recursive {
   our $state;

   ...

   if (...) {
      local $state = ~~~;
      recursive();
   }

   ...
}

##</code><code>##

my $var = 1;
our $alias;
*alias = \$var;
$alias = 2;
print("$var\n");   # 2