reserve i, j, m, n, k for Nat,
  x, y for set,
  K for Field,
  a,a1 for Element of K;
reserve V1,V2,V3 for finite-dimensional VectSp of K,
  f for Function of V1,V2,

  b1,b19 for OrdBasis of V1,
  B1 for FinSequence of V1,
  b2 for OrdBasis of V2,
  B2 for FinSequence of V2,

  B3 for FinSequence of V3,
  v1,w1 for Element of V1,
  R,R1,R2 for FinSequence of V1,
  p,p1,p2 for FinSequence of K;

theorem
  for A,B be Matrix of len b1,len b2,K st 
  Mx2Tran(A,b1,b2) = Mx2Tran(B,b1,b2) holds A = B
proof
  let A,B be Matrix of len b1,len b2,K;
  assume Mx2Tran(A,b1,b2)=Mx2Tran(B,b1,b2);
  hence A = AutMt(Mx2Tran(B,b1,b2),b1,b2) by Th36
    .= B by Th36;
end;
