y ∑(∑|aik|-|bD22 j=1i=1k=1 ≤C∑|aik2)(∑|bk72)2 j=1i=1k=1 k=1 {∑(∑|b2)I∑(∑|ak2)}2 j=1k=1 i=1k=1 ik 以|bk i=1k=1 k=lj lAl ‖!B2 1 1 1 1 2 [(| | | |) ] = = =  • n j m i l k ai k bkj 2 1 1 2 1 1 1 2 [(| | ) (| | )] = = = =  • l k kj n j m i l k ai k b 2 1 1 1 2 2 1 1 1 2 (| | ) (| | ) = = = =  • l k n j kj m i l k ai k b 2 2 = || A||m • || B||m 2 1 1 1 1 2 1 2 {  (  | | ) [( | | )]} = = = = = • n j m i l k ik l k bk j a