sub PrintRegExVar {
   print "Inside called sub: $1 $2\n";
}

$_ = "abcde";
if (/(.)(.)/) { # first two
  if (/(.)(.)$/) { # last two
    #
    # This prints "d e"
    #
    print "inner: $1 $2\n";
    &PrintRegExVar;
  }
  #
  # This also prints "d e"
  #
  print "outer: $1 $2\n";
  &PrintRegExVar;
}

                 
$_ = "abcde";
if (/(.)(.)/) { # first two
  { # ADDED EXTRA BLOCK
     if (/(.)(.)$/) { # last two
       #
       # This prints "d e"
       #
       print "inner: $1 $2\n";
       &PrintRegExVar;
     }
  } # ADDED EXTRA BLOCK
  #
  # This prints "a b"
  #
  print "outer: $1 $2\n";
  &PrintRegExVar;
}

__END__

inner: d e
Inside called sub: d e
outer: d e
Inside called sub: d e
inner: d e
Inside called sub: d e
outer: a b
Inside called sub: a b