=∑(xk|·∑|aikl) k=1 ≤∑(∑xk|·∑ai1) =1k=1 ∑∑aiD·∑|xk i=lk=1 k=1 =‖4lm1°lxll   = = = = • n k k n i n k aik x 1 1 1 ( | |) | | 1 || || || || 1 = A m • x (| | | | ) 1 1   = = =  n k n i xk aik ( | | | | ) 1 1 1    = = =   n k n i ik n k xk a