List exchange - listen elemente tauschen
Tensor - Dyadic Product Version
Tensor(zz,ss,nn):=Transpose(Element(Identity(nn), zz)) {Element(Identity(nn), ss)}
T(zz,ss,nn):=Identity(nn)+Tensor(zz,ss,nn) -Tensor(zz,zz,nn) +Tensor(ss,zz,nn)-Tensor(ss,ss,nn)
Sum(Sequence(Tensor(j+1,j,7),j,1,6))+Tensor(1,7,7)
Tx = Transpose(xT)