Show that V += V2, where V is the value of a swaption to pay a fixed rate of 5K and receive LIBOR between times T1 and T2, f is the value of a forward swap to receive a fixed rate of sx and pay LIBOR between times T and T2, and V2 is the value of a swaption to receive a fixed rate of sx between times T and 72. Deduce that V = V2 when SK equals the current forward swap rate. P-987