private int getValueTruthTable(String symbol, int rowTruthTable)
	{
		int positionCol = positionTruthTable.get(symbol);				//lookup position of symbol in truth table
		int value = truthTable.get(rowTruthTable).get(positionCol);		//retrieve value of symbol at particular row(rowTruthTable) in truth table
		return value;													//return value
	}