Ring Theory.
(* Title: HOL/Integ/IntRing.thy
ID: $Id$
Author: Tobias Nipkow and Markus Wenzel
Copyright 1996 TU Muenchen
The integers form a commutative ring.
With an application of Lagrange's lemma.
*)
IntRing = IntRingDefs + Lagrange +
instance int :: add_semigroup (zadd_assoc)
instance int :: add_monoid (zero_int_def,zadd_0,zadd_0_right)
instance int :: add_group (left_inv_int,minus_inv_int)
instance int :: add_agroup (zadd_commute)
instance int :: ring (zmult_assoc,zadd_zmult_distrib2,zadd_zmult_distrib)
instance int :: cring (zmult_commute)
end