concrete QuerySpa of Query = {
  lincat 
    Answer, Question, Object = Str ;

  lin 
    Even x = x ++ "es" ++ "par" ;
    Odd  x = x ++ "es" ++ "impar" ;
    Prime x = x  ++ "es" ++ "primo" ;
    Number n = n.s ;

    Yes = "si" ;
    No = "no" ;

}