let F be Field; for E being FieldExtension of F
for K being F -extending FieldExtension of F
for h being F -fixing Monomorphism of E,K
for p being non constant Element of the carrier of (Polynom-Ring F) st p splits_in E holds
h .: (Roots (E,p)) c= the carrier of E
let E be FieldExtension of F; for K being F -extending FieldExtension of F
for h being F -fixing Monomorphism of E,K
for p being non constant Element of the carrier of (Polynom-Ring F) st p splits_in E holds
h .: (Roots (E,p)) c= the carrier of E
let K be F -extending FieldExtension of F; for h being F -fixing Monomorphism of E,K
for p being non constant Element of the carrier of (Polynom-Ring F) st p splits_in E holds
h .: (Roots (E,p)) c= the carrier of E
let h be F -fixing Monomorphism of E,K; for p being non constant Element of the carrier of (Polynom-Ring F) st p splits_in E holds
h .: (Roots (E,p)) c= the carrier of E
let p be non constant Element of the carrier of (Polynom-Ring F); ( p splits_in E implies h .: (Roots (E,p)) c= the carrier of E )
assume AS:
p splits_in E
; h .: (Roots (E,p)) c= the carrier of E
H:
( Roots (E,p) = { a where a is Element of E : a is_a_root_of p,E } & Roots (K,p) = { a where a is Element of K : a is_a_root_of p,K } )
by FIELD_4:def 4;
now for o being object st o in h .: (Roots (E,p)) holds
o in the carrier of Elet o be
object ;
( o in h .: (Roots (E,p)) implies o in the carrier of E )assume
o in h .: (Roots (E,p))
;
o in the carrier of Ethen consider x being
object such that B:
(
x in dom h &
x in Roots (
E,
p) &
o = h . x )
by FUNCT_1:def 6;
consider a being
Element of
E such that C:
(
a = x &
a is_a_root_of p,
E )
by B, H;
Ext_eval (
p,
a)
= 0. E
by C, FIELD_4:def 2;
then 0. K =
h . (Ext_eval (p,a))
by RING_2:6
.=
Ext_eval (
p,
(h . a))
by fixeval
;
then
h . a is_a_root_of p,
K
by FIELD_4:def 2;
then
h . a in Roots (
K,
p)
by H;
then
h . a in Roots (
E,
p)
by AS, lemNor2bb;
hence
o in the
carrier of
E
by C, B;
verum end;
hence
h .: (Roots (E,p)) c= the carrier of E
; verum