
theorem Th28:
  for z be G_RAT, i be Element of RAT holds RSc_Mult.(i,z) = i*z
  proof
    let z be G_RAT, i be Element of RAT;
    i in RAT & z in G_RAT_SET;
    hence RSc_Mult.(i,z) = multcomplex.(i,z) by FUNCT_1:49,ZFMISC_1:87
    .= i*z by BINOP_2:def 5;
  end;
