private void backTrackToUnit()
	{
		if (myUnitStepMap==null)
			return;
		int index=0;
		while (index<myAnswer.size())
		{
			for (ArrayList <Production> key: myUnitStepMap.keySet())
			{
				if (myUnitStepMap.get(key).equals(myAnswer.get(index)))
				{
					myAnswer.remove(index);
					int c=0;
					for (Production p : key)
					{
						myAnswer.add(index+c, p);
						c++;
					}
					index=index+key.size()-1;
				}
			}
			index++;
		}
		//System.out.println("After Backtracking Unit Step = "+myAnswer);
		
	}