※ 引述《Evenroll (研二不是应该很清闲吗？)》之铭言：
: also,
: I found that if there is an alpha_i that 0 < alpha_i < C
: then the index i will belong to I_up and I_low at the same time.
yes.
: I also find that in the example in ch 6.3,
: even if alpha = [1,1,0,0]' at the first iteration
: the example still could find I_up = {2, 4}, I_low = {1, 3}
: I couldn't understand how he find I_up and I_low.
: Is there anything I misunderstand in the algorithm?