reserve i,j for Nat;

theorem
  for K being Field, a being Element of K, A being Matrix of K holds
  Indices (a*A) = Indices A
proof
  let K be Field, a be Element of K, A be Matrix of K;
  len (a*A)=len A & width (a*A)=width A by MATRIX_3:def 5;
  hence thesis by FINSEQ_3:29;
end;
