theorem Th48:
  Product mlt(R1,R2) = Product R1 * Product R2
proof
  reconsider R1,R2 as i-element FinSequence of COMPLEX by FINSEQ_1:102;
  reconsider T1=R1, T2=R2 as Element of i-tuples_on COMPLEX
  by FINSEQ_2:131;
  Product (mlt(R1,R2)) = multcomplex.(multcomplex$$T1,multcomplex$$T2)
  by SETWOP_2:35
  .= Product R1 * Product R2 by BINOP_2:def 5;
  hence thesis;
end;
