  We outline an algorithm for construction of functional bases of absolute
invariants under the rotation group for sets of rank 2 tensors and vectors in
the Euclidean space of arbitrary dimension. We will use our earlier results for
symmetric tensors and add results for sets including antisymmetric tensors of
rank 2.
  That allowed, in particular, constructing of functional bases of differential
invariants for vector functions, in particular, of first-order invariants of
Poincar\'e algebra (invariance algebra of Maxwell equations for vector
potential).
