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forward_discount_factor

The forward discount factor is a number D - generally between 0 and 1 - that equals the cash amount one would agree today to pay at some fixed future time T* in exchange for one currency unit received at some even later time T.
For demonstration let's assume the currency is USD.
Then one would agree today to pay D at the future time T* for the promise to receive 1 US Dollar at T.
To the extent that this promise is deemed to be 100% reliable, the forward discount factor is also termed as riskless forward discount factor.
In the special case when T* equals today's date, the forward discount factor becomes identical with a
discount factor maturing at time T.