This script calculates the fair value of gold, which is set as an input parameter. It then gets the current price of gold and calculates the gap between the price and the fair value. If the gap is positive, it enters a long trade, and if it's negative, it enters a short trade.
The script also uses proper risk management techniques by setting a stop loss and take profit for each trade. The plot() function is used to display the fair value and gap on the chart.
Please note that this is just an example script, and you should customize it based on your specific trading strategy and criteria. It's also important to backtest your strategy and refine it before using it with real money.