 reserve n for Nat;

theorem Th17:
   for R being Ring, S being R-homomorphic Ring
   for h being Homomorphism of R,S
   for F being FinSequence of R, a being Element of R holds
   h.(Sum(F^<*a*>)) = h.(Sum F) + h.a
   proof
     let R be Ring, S be R-homomorphic Ring; let h be Homomorphism of R,S;
     let F be FinSequence of R, a be Element of R;
     thus h.(Sum(F^<*a*>)) = h.(Sum F + Sum(<*a*>)) by RLVECT_1:41
                     .= h.(Sum F) + h.(Sum<*a*>) by VECTSP_1:def 20
                     .= h.(Sum F) + h.a by RLVECT_1:44;
   end;
