# Theory PID

Up to index of Isabelle/HOL/HOL-Algebra

theory PID
imports Ideal
begin

    (*
        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