#!/usr/bin/env perl
use strict;
use warnings;

my $x = '((A & B)\' | (A & C & (A & B & D)\'))'; 

print "Given: $x\n"; 

#$x =~ s/(\(.*?\))\'/\!$1/g; 
$x =~ s/(\([^(]*?\))\'/\!$1/g;

print "Calculated: ",$x,"\n";

##</code><code>##

Given: ((A & B)' | (A & C & (A & B & D)'))
Calculated: (!(A & B) | (A & C & !(A & B & D)))