
theorem Th1:
  for C being CategoryStr, f being morphism of C
  st C is non empty holds f in the carrier of C
  proof
    let C be CategoryStr;
    let f be morphism of C;
    assume C is non empty;
    then f in Mor C by SUBSET_1:def 1;
    hence f in the carrier of C by CAT_6:def 1;
  end;
