Classification of pairs of subspaces in scalar product spaces

Up to the classification of Hermitian forms a classification has been given of triplesP=(V_F; U₁, U₂), consisting of a finite dimensional vector space V over a field of characteristic 2 with a symmetric, or a skew-symmetric, or Hermitian form F and two subspaces U₁, U₂. Two triplesP andP are identified with each other if there exists an isometry V_f V_f such that (U_i)=U_i, i=1, 2.Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 42, No. 4, pp. 549–554, April, 1990.