(Program
{ (Equal
  {-(Send
    {-(Identifier)-})-}
  {-(Send
    {-(Identifier)-})-})
->(Comparison
  {+(Send
    {+(Identifier)+})+}
  {+(Send
    {+(Identifier)+})+}) }
{+(Matches
  {+(Send
    {+(Identifier)+})+}
  {+(Send
    {+(Identifier)+})+})+}
{+(Assignment
  {+(Identifier)+}
  {+(Not
    {+(Send
      {+(Identifier)+})+})+})+}
{-(Not
  {-(Equal
    {-(Send
      {-(Identifier)-})-}
    {-(Send
      {-(Identifier)-})-})-})-}
{-(Equal
  {-(Send
    {-(Identifier)-})-}
  {-(Send
    {-(Identifier)-})-})-})