You may occasionally see some investment returns or financial ratios listed as "Infinity":
This is not a mistake and does literally mean that that particular rate of return or ratio is infinite for that specific property.
In that case, you will have no capital invested in the property after the refinance is complete. So any metric that shows a return on your invested capital (ex. Cash on Cash, ROI, IRR, etc.), is going to be infinite.
Another way to think about this is that you were able to create a cash flow stream or a profit without actually investing any capital in the transaction.