src/HOL/Algebra/abstract/Field.thy

move class perfect_space into RealVector.thy;
use not_open_singleton as perfect_space class axiom;
generalize some lemmas to class perfect_space;

(*  Author: Clemens Ballarin, started 15 November 1997

Properties of abstract class field.
*)

theory Field
imports Factor PID
begin

instance field < "domain"
  apply intro_classes
   apply (rule field_one_not_zero)
  apply (erule field_integral)
  done

instance field < factorial
  apply intro_classes
  apply (erule field_fact_prime)
  done

end