reserve i,j for Nat;
reserve A,B for Ring;
reserve K, L for Field;

theorem Th50:
  for x be Element of F_Complex, z, w be Element of FQ(x) holds
  (FQ_mult(x)).(z,w) = z*w
  proof
    let x be Element of F_Complex;
    let z, w be Element of FQ(x);
    thus (FQ_mult(x)).(z,w) = multcomplex.(z,w) by FUNCT_1:49,ZFMISC_1:87
    .= z*w by BINOP_2:def 5;
  end;
