theorem Th66:
  for v being constructor OperSymbol of C
  st the_result_sort_of v = an_Adj C & len p = len the_arity_of v
  holds v-trm p is positive quasi-adjective of C
proof
  let v be constructor OperSymbol of C such that
A1: the_result_sort_of v = an_Adj C;
  assume
A2: len p = len the_arity_of v;
  then reconsider a = v-trm p as expression of C, an_Adj C by A1,Th52;
  a is positive
  by A2,Th54;
  hence thesis;
end;
