theorem Th14:
  <*p,id field f,p*> is SFHT of D
  proof
    set i = id field f;
A1: i is BinominativeFunction of D by PARTPR_2:5;
    for d holds d in dom p & p.d = TRUE & d in dom i & i.d in dom p implies
    p.(i.d) = TRUE by FUNCT_1:17;
    then <*p,i,p*> in SFHTs(D) by A1;
    hence thesis;
  end;
