src/HOL/Algebra/poly/LongDiv.thy
author obua
Tue, 11 May 2004 20:11:08 +0200
changeset 14738 83f1a514dcb4
parent 14723 b77ce15b625a
child 15481 fc075ae929e4
permissions -rw-r--r--
changes made due to new Ring_and_Field theory
     1 (*
     2     Experimental theory: long division of polynomials
     3     $Id$
     4     Author: Clemens Ballarin, started 23 June 1999
     5 *)
     6 
     7 theory LongDiv = PolyHomo:
     8 
     9 consts
    10   lcoeff :: "'a::ring up => 'a"
    11   eucl_size :: "'a::ring => nat"
    12 
    13 defs
    14   lcoeff_def: "lcoeff p == coeff p (deg p)"
    15   eucl_size_def: "eucl_size p == (if p = 0 then 0 else deg p+1)"
    16 
    17 lemma SUM_shrink_below_lemma:
    18   "!! f::(nat=>'a::ring). (ALL i. i < m --> f i = 0) --> 
    19   setsum (%i. f (i+m)) {..d} = setsum f {..m+d}"
    20   apply (induct_tac d)
    21   apply (induct_tac m)
    22   apply (simp)
    23   apply (force)
    24   apply (simp)
    25   apply (subst ab_semigroup_add.add_commute[of m])
    26   apply (simp)
    27   done
    28 
    29 end
    30