
theorem Th54:
  for L being domRing, p being non-zero Polynomial of L st len p =
  1 holds degree BRoots p = 0
proof
  let L be domRing, p being non-zero Polynomial of L;
  assume len p = 1;
  then Roots p = {} by Th43;
  then support BRoots p = {} by Def8;
  then BRoots p = EmptyBag the carrier of L by PRE_POLY:81;
  hence thesis by Th8;
end;
