reserve s for set,
  i,j for Nat,
  c,c1,c2,c3 for Complex,
  F,F1,F2 for complex-valued FinSequence,
  R,R1,R2 for i-element complex-valued FinSequence;

theorem
  c*<*c1*> = <*c*c1*>
proof
  reconsider s=c, s1=c1 as Element of COMPLEX by XCMPLX_0:def 2;
  s*<*s1*> = <*(multcomplex[;](s,id COMPLEX)).s1*> by FINSEQ_2:35
          .= <*c*c1*> by Lm1;
  hence thesis;
end;
