deffunc H1( set ) -> set = $1;
let R be non empty non trivial right_complementable Abelian add-associative right_zeroed associative commutative well-unital distributive doubleLoopStr ; :: thesis: for X being infinite Ordinal holds not Polynom-Ring X,R is Noetherian
let X be infinite Ordinal; :: thesis: not Polynom-Ring X,R is Noetherian
assume A1: Polynom-Ring X,R is Noetherian ; :: thesis: contradiction
reconsider f0 = X --> (0. R) as Function of X,the carrier of R ;
deffunc H2( Element of X) -> Series of X,R = 1_1 $1,R;
set tcR = the carrier of R;
A2: for d1, d2 being Element of X st H2(d1) = H2(d2) holds
d1 = d2 by Th14;
the carrier of R c= the carrier of R ;
then reconsider cR = the carrier of R as non empty Subset of the carrier of R ;
set S = { (1_1 n,R) where n is Element of X : n in NAT } ;
set tcPR = the carrier of (Polynom-Ring X,R);
A3: NAT c= X by CARD_3:102;
0 in NAT ;
then reconsider 0X = 0 as Element of X by A3;
A4: { (1_1 n,R) where n is Element of X : n in NAT } c= the carrier of (Polynom-Ring X,R)
proof
let x be set ; :: according to TARSKI:def 3 :: thesis: ( not x in { (1_1 n,R) where n is Element of X : n in NAT } or x in the carrier of (Polynom-Ring X,R) )
assume x in { (1_1 n,R) where n is Element of X : n in NAT } ; :: thesis: x in the carrier of (Polynom-Ring X,R)
then ex n being Element of X st
( x = 1_1 n,R & n in NAT ) ;
hence x in the carrier of (Polynom-Ring X,R) by POLYNOM1:def 27; :: thesis: verum
end;
1_1 0X,R in { (1_1 n,R) where n is Element of X : n in NAT } ;
then reconsider S = { (1_1 n,R) where n is Element of X : n in NAT } as non empty Subset of the carrier of (Polynom-Ring X,R) by A4;
consider C being non empty finite Subset of the carrier of (Polynom-Ring X,R) such that
A5: C c= S and
A6: C -Ideal = S -Ideal by A1, IDEAL_1:99;
set CN = { H1(n) where n is Element of X : H2(n) in C } ;
A7: C is finite ;
A8: { H1(n) where n is Element of X : H2(n) in C } is finite from FUNCT_7:sch 2(A7, A2);
A9: { H1(n) where n is Element of X : H2(n) in C } c= NAT
proof
let x be set ; :: according to TARSKI:def 3 :: thesis: ( not x in { H1(n) where n is Element of X : H2(n) in C } or x in NAT )
assume x in { H1(n) where n is Element of X : H2(n) in C } ; :: thesis: x in NAT
then consider n being Element of X such that
A10: x = n and
A11: 1_1 n,R in C ;
1_1 n,R in S by A5, A11;
then ex m being Element of X st
( 1_1 n,R = 1_1 m,R & m in NAT ) ;
hence x in NAT by A10, Th14; :: thesis: verum
end;
consider c being Element of C;
c in C ;
then c in S by A5;
then consider cn being Element of X such that
A12: c = 1_1 cn,R and
A13: cn in NAT ;
reconsider cn = cn as Element of NAT by A13;
cn in { H1(n) where n is Element of X : H2(n) in C } by A12;
then reconsider CN = { H1(n) where n is Element of X : H2(n) in C } as non empty finite Subset of NAT by A8, A9;
reconsider mm = max CN as Element of NAT by ORDINAL1:def 13;
reconsider m1 = mm + 1 as Element of NAT ;
m1 in NAT ;
then reconsider m2 = m1 as Element of X by A3;
( 1_1 m2,R in S & S c= S -Ideal ) by IDEAL_1:def 15;
then consider lc being LinearCombination of C such that
A14: 1_1 m2,R = Sum lc by A6, IDEAL_1:60;
reconsider ev = f0 +* m2,(1_ R) as Function of X,R ;
consider E being FinSequence of [:the carrier of (Polynom-Ring X,R),the carrier of (Polynom-Ring X,R),the carrier of (Polynom-Ring X,R):] such that
A15: E represents lc by IDEAL_1:35;
set P = Polynom-Evaluation X,R,ev;
deffunc H3( Nat) -> Element of the carrier of R = (((Polynom-Evaluation X,R,ev) . ((E /. $1) `1 )) * ((Polynom-Evaluation X,R,ev) . ((E /. $1) `2 ))) * ((Polynom-Evaluation X,R,ev) . ((E /. $1) `3 ));
consider LC being FinSequence of the carrier of R such that
A16: len LC = len lc and
A17: for k being Nat st k in dom LC holds
LC . k = H3(k) from FINSEQ_2:sch 1();
now
let i be set ; :: thesis: ( i in dom LC implies ex u, v being Element of R ex a being Element of cR st LC /. i = (u * a) * v )
assume A18: i in dom LC ; :: thesis: ex u, v being Element of R ex a being Element of cR st LC /. i = (u * a) * v
then reconsider k = i as Element of NAT ;
reconsider a = (Polynom-Evaluation X,R,ev) . ((E /. k) `2 ) as Element of cR ;
reconsider u = (Polynom-Evaluation X,R,ev) . ((E /. k) `1 ), v = (Polynom-Evaluation X,R,ev) . ((E /. k) `3 ) as Element of R ;
take u = u; :: thesis: ex v being Element of R ex a being Element of cR st LC /. i = (u * a) * v
take v = v; :: thesis: ex a being Element of cR st LC /. i = (u * a) * v
take a = a; :: thesis: LC /. i = (u * a) * v
thus LC /. i = LC . k by A18, PARTFUN1:def 8
.= (u * a) * v by A17, A18 ; :: thesis: verum
end;
then reconsider LC = LC as LinearCombination of cR by IDEAL_1:def 9;
A19: now
let i be Element of NAT ; :: thesis: ( i in dom LC implies LC . i = 0. R )
A20: now end;
assume A21: i in dom LC ; :: thesis: LC . i = 0. R
then i in dom lc by A16, FINSEQ_3:31;
then reconsider y = (E /. i) `2 as Element of C by A15, IDEAL_1:def 12;
y in C ;
then y in S by A5;
then consider n being Element of X such that
A22: y = 1_1 n,R and
n in NAT ;
n in CN by A22;
then A23: ev . n = (X --> (0. R)) . n by A20, FUNCT_7:34
.= 0. R by FUNCOP_1:13 ;
A24: Support (1_1 n,R) = {(UnitBag n)} by Th13;
A25: (Polynom-Evaluation X,R,ev) . (1_1 n,R) = eval (1_1 n,R),ev by POLYNOM2:def 5
.= ((1_1 n,R) . (UnitBag n)) * (eval (UnitBag n),ev) by A24, POLYNOM2:21
.= (1_ R) * (eval (UnitBag n),ev) by Th12
.= (1_ R) * (ev . n) by Th11
.= 0. R by A23, VECTSP_1:36 ;
thus LC . i = (((Polynom-Evaluation X,R,ev) . ((E /. i) `1 )) * ((Polynom-Evaluation X,R,ev) . ((E /. i) `2 ))) * ((Polynom-Evaluation X,R,ev) . ((E /. i) `3 )) by A17, A21
.= (0. R) * ((Polynom-Evaluation X,R,ev) . ((E /. i) `3 )) by A22, A25, VECTSP_1:36
.= 0. R by VECTSP_1:36 ; :: thesis: verum
end;
dom (X --> (0. R)) = X by FUNCOP_1:19;
then A26: ev . m2 = 1_ R by FUNCT_7:33;
A27: Support (1_1 m2,R) = {(UnitBag m2)} by Th13;
A28: (Polynom-Evaluation X,R,ev) . (1_1 m2,R) = eval (1_1 m2,R),ev by POLYNOM2:def 5
.= ((1_1 m2,R) . (UnitBag m2)) * (eval (UnitBag m2),ev) by A27, POLYNOM2:21
.= (1_ R) * (eval (UnitBag m2),ev) by Th12
.= (1_ R) * (ev . m2) by Th11
.= 1_ R by A26, GROUP_1:def 5 ;
for k being set st k in dom LC holds
LC . k = (((Polynom-Evaluation X,R,ev) . ((E /. k) `1 )) * ((Polynom-Evaluation X,R,ev) . ((E /. k) `2 ))) * ((Polynom-Evaluation X,R,ev) . ((E /. k) `3 )) by A17;
then (Polynom-Evaluation X,R,ev) . (Sum lc) = Sum LC by A15, A16, Th24
.= 0. R by A19, POLYNOM3:1 ;
hence contradiction by A14, A28, VECTSP_1:36, VECTSP_1:def 13; :: thesis: verum