anchor.diff:  procedure Expression;
   begin
       Term;
  -    EmitLn('MOVE D0,D1');
  +    EmitLn('movq %rax, %rbx');
       case Look of
       '+': Add;
       '-': Subtract;
  
positive.code: { Parse and Translate an Expression }
  procedure Term;
  begin
      EmitLn('mov %eax, $' + GetNum)
  end;
  {---------------------------------------------------------------}
  
  
negative.code: 
  procedure Init;
  begin
      { Grab the next character. Not doing token lookahead yet.}
      GetChar;
      { pre progoram boiler plate }
      EmitLn('.text');
      EmitLn('.globl _main');
      EmitLn('    _main:');
      EmitLn('    subq $8, %rsp');
  end;
  
  procedure Post;
  