6. [8 marks] Consider the sequence 10,21,... defined by 20 = 0, 21 = 1, and ri = 1;-1 + 1;-2 for all i>2. Consider the following algorithm that attempts to compute the value In, given an n > 0. Algorithm 6 1: //pre: (n EZ) A (n > 0) 2: if n == 0 then 3: b= 0 4: else 5 + 0 6:51 in1 //LoopInv: 9: while i<>