(*
Principle ideal domains
$Id: PID.thy,v 1.2 2005/09/17 18:49:14 wenzelm Exp $
Author: Clemens Ballarin, started 5 October 1999
*)
theory PID imports Ideal begin
instance pid < factorial
apply intro_classes
apply (rule TrueI)
apply (erule pid_irred_imp_prime)
done
end