code: function eq(x, y)
  {
  	var stack = [];
  	var isEqual = eqHelp(x, y, 0, stack);
  	var pair;
  	while (isEqual && (pair = stack.pop()))
  	{
  		isEqual = eqHelp(pair.x, pair.y, 0, stack);
  	}
  	return isEqual;
  }
docs: COMPARISONS