and has the following
spectral decomposition:

where *y**i*Î **C**n is given by

q*A*Î **R**n´n with real eigenvalue
*l*Î **R** Þ real eigenvector *x*Î **R**n

q*A*
is *Hermitian*,i.e., *A=A** Þ $ unitary *U* such that *A=U**L**U** and *L**=*diag{*l**1 *, *l**2* , … , *l**n*} is real.