src/HOL/Algebra/abstract/Factor.thy
author wenzelm
Tue, 16 May 2006 13:01:23 +0200
changeset 19641 f1de44e61ec1
parent 17479 68a7acb5f22e
child 20318 0e0ea63fe768
permissions -rw-r--r--
replaced low-level Term.str_of by Display.raw_string_of_term (should actually use Display.string_of_term);

(*
    Factorisation within a factorial domain
    $Id$
    Author: Clemens Ballarin, started 25 November 1997
*)

theory Factor imports Ring begin

constdefs
  Factorisation :: "['a::ring, 'a list, 'a] => bool"
  (* factorisation of x into a list of irred factors and a unit u *)
  "Factorisation x factors u ==
     x = foldr op* factors u &
     (ALL a : set factors. irred a) & u dvd 1"

end