theorem Th54: :: RLVECT_1:58 NUMERAL1:1
  Sum(cF1^cF2)=Sum(cF1)+Sum(cF2)
proof
  thus Sum(cF1^cF2)=addcomplex.(Sum(cF1),Sum(cF2)) by Th41
    .= Sum(cF1)+Sum(cF2) by BINOP_2:def 3;
end;
