Hi Saksham. See, there are two things- select mortality and ultimate mortality. In the AM 92 table, select period is 2 years. (we denote select period by s). Which means, for duration ≥2, the select mortality will be same as ultimate mortality. ( [x] is denoted for select and x is for ultimate ). Eg. L[46]+1 ≠ L47 (since duration is less than 2). But L[46]+2 = L48 (since select mortaility is same as ultimate now for s≥2). Notice that on page26, there is a condition for the formula you are talking about. That is used for t=s-1, .....,1,0. Means if select period is 2, we can only use this formula for t= 1,0. And for rest, L[x]+s = Lx+s. In the example of page27, select period is given 2. (See in the given table the mortality is different for durations 0 and 1 and then same for duration≥2). Thats why L[46]+2 = L48 Hope this helps!
