So bewilderingly. about closure

[flw]

C:\>cat ttt.pl
use strict;
use warnings;

{
  my $x = 'A';
  sub f { sub { $x++ }       }
  sub g { sub { $x++ } if $x }
}

my $F=f();
my $G=g();

print $F->(),$G->(),"," for 1..4;
print "\n";

C:\>ttt.pl
0A,1B,2C,3D,

C:\>