More rings stuff (#83)

This commit is contained in:
Patrick Stevens
2019-11-23 13:53:54 +00:00
committed by GitHub
parent 660d7aa27c
commit 2ed7bd8044
12 changed files with 260 additions and 17 deletions

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@@ -4,6 +4,7 @@ open import LogicalFormulae
open import Groups.Groups
open import Groups.Homomorphisms.Definition
open import Groups.Definition
open import Groups.Lemmas
open import Numbers.Naturals.Naturals
open import Setoids.Orders
open import Setoids.Setoids
@@ -13,6 +14,7 @@ open import Rings.Definition
open import Rings.Homomorphisms.Definition
open import Groups.Homomorphisms.Lemmas
open import Rings.Subrings.Definition
open import Rings.Cosets
open import Rings.Isomorphisms.Definition
open import Groups.Isomorphisms.Definition
@@ -22,10 +24,22 @@ module Rings.Ideals.FirstIsomorphismTheorem {a b c d : _} {A : Set a} {B : Set c
open import Rings.Quotients.Definition R1 R2 hom
open import Rings.Homomorphisms.Image hom
open import Rings.Homomorphisms.Kernel hom
open Setoid T
open Equivalence eq
open import Groups.FirstIsomorphismTheorem (RingHom.groupHom hom)
ringFirstIsomorphismTheorem : RingsIsomorphic (cosetRing R1 ringKernelIsIdeal) (subringIsRing R2 imageGroupSubring)
RingsIsomorphic.f ringFirstIsomorphismTheorem = GroupsIsomorphic.isomorphism groupFirstIsomorphismTheorem
RingHom.preserves1 (RingIso.ringHom (RingsIsomorphic.iso ringFirstIsomorphismTheorem)) = RingHom.preserves1 hom
RingHom.ringHom (RingIso.ringHom (RingsIsomorphic.iso ringFirstIsomorphismTheorem)) = RingHom.ringHom hom
GroupHom.groupHom (RingHom.groupHom (RingIso.ringHom (RingsIsomorphic.iso ringFirstIsomorphismTheorem))) = GroupHom.groupHom (RingHom.groupHom hom)
GroupHom.wellDefined (RingHom.groupHom (RingIso.ringHom (RingsIsomorphic.iso ringFirstIsomorphismTheorem))) {x} {y} x=y = transferToRight (Ring.additiveGroup R2) t
where
t : f x +B Group.inverse (Ring.additiveGroup R2) (f y) Ring.0R R2
t = transitive (Ring.groupIsAbelian R2) (transitive (Group.+WellDefined (Ring.additiveGroup R2) (symmetric (homRespectsInverse (RingHom.groupHom hom))) reflexive) (transitive (symmetric (GroupHom.groupHom (RingHom.groupHom hom))) x=y))
RingIso.bijective (RingsIsomorphic.iso ringFirstIsomorphismTheorem) = GroupIso.bij (GroupsIsomorphic.proof groupFirstIsomorphismTheorem)
ringFirstIsomorphismTheorem' : RingsIsomorphic quotientByRingHom (subringIsRing R2 imageGroupSubring)
RingsIsomorphic.f ringFirstIsomorphismTheorem' a = f a , (a , reflexive)
RingHom.preserves1 (RingIso.ringHom (RingsIsomorphic.iso ringFirstIsomorphismTheorem')) = RingHom.preserves1 hom