You want to subtract off the value of a perpetuity that starts after 2T, six-month intervals, so this is the present value of the perpetuity that starts after 2T, six-month intervals.

所以就要从永续债券价格里减去,2T期以后,每六月一期券息的贴现值,这部分是永久债券从第2T期后,每半年一期券息的现值

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