A perpetuity is the closed form for a level cash flow forever.
Level cash flow forever
A level perpetuity is a projected cash flow that continues forever at the same amount.
level perpetuity: C,C,C,…
Closed form
The closed form present value is cash flow divided by discount rate.
PV=rC
Level perpetuity value
With projected cash flow of $100.00 per year and discount rate 10%, the DCF value under these assumptions is $1,000.00.
PV=10%$100.00=$1,000.00