Matrix inverse square root, n=10.
FN Object: 1 MPI processes
  type: invsqrt
    Inverse square root: +0.5*(+0.9*x)^(-1/2)
  f(2.2)=0.355335
  f'(2.2)=-0.0807578
||S*S*A-I||_F < 100*eps
||S*S*A-I||_F < 100*eps
||S*S*A-I||_F < 100*eps
