let n be non empty Ordinal; :: thesis: for T being connected admissible TermOrder of n
for L being non empty non degenerated right_complementable almost_left_invertible associative commutative well-unital distributive add-associative right_zeroed doubleLoopStr holds
not for P being Subset of (Polynom-Ring n,L) holds P is_Groebner_basis_wrt T

let T be connected admissible TermOrder of n; :: thesis: for L being non empty non degenerated right_complementable almost_left_invertible associative commutative well-unital distributive add-associative right_zeroed doubleLoopStr holds
not for P being Subset of (Polynom-Ring n,L) holds P is_Groebner_basis_wrt T

let L be non empty non degenerated right_complementable almost_left_invertible associative commutative well-unital distributive add-associative right_zeroed doubleLoopStr ; :: thesis: not for P being Subset of (Polynom-Ring n,L) holds P is_Groebner_basis_wrt T
set 1bag = (EmptyBag n) +* {} ,1;
reconsider 1bag = (EmptyBag n) +* {} ,1 as Element of Bags n by POLYNOM1:def 14;
A1: {} in n by ORDINAL1:24;
dom (EmptyBag n) = n by PBOOLE:def 3;
then 1bag . {} = 1 by A1, FUNCT_7:33;
then A2: EmptyBag n <> 1bag by POLYNOM1:56;
set p = ((1. L) | n,L) +* 1bag,(1. L);
reconsider p = ((1. L) | n,L) +* 1bag,(1. L) as Function of Bags n,L ;
reconsider p = p as Series of n,L ;
A3: 1. L <> 0. L ;
A4: dom ((1. L) | n,L) = Bags n by FUNCT_2:def 1;
then A5: p . 1bag = 1. L by FUNCT_7:33;
then A6: p <> 0_ n,L by A3, POLYNOM1:81;
A7: p . (EmptyBag n) = ((1. L) | n,L) . (EmptyBag n) by A2, FUNCT_7:34
.= (1_ n,L) . (EmptyBag n) by POLYNOM7:20
.= 1. L by POLYNOM1:84 ;
A8: now
let u be bag of n; :: thesis: ( u <> EmptyBag n & u <> 1bag implies p . u = 0. L )
assume A9: ( u <> EmptyBag n & u <> 1bag ) ; :: thesis: p . u = 0. L
then p . u = ((1. L) | n,L) . u by FUNCT_7:34;
then p . u = (1_ n,L) . u by POLYNOM7:20;
hence p . u = 0. L by A9, POLYNOM1:84; :: thesis: verum
end;
A10: now end;
now
let u' be set ; :: thesis: ( u' in Support p implies u' in {(EmptyBag n),1bag} )
assume A12: u' in Support p ; :: thesis: u' in {(EmptyBag n),1bag}
then reconsider u = u' as Element of Bags n ;
A13: p . u <> 0. L by A12, POLYNOM1:def 9;
now
assume not u in {(EmptyBag n),1bag} ; :: thesis: contradiction
then ( u <> EmptyBag n & u <> 1bag ) by TARSKI:def 2;
hence contradiction by A8, A13; :: thesis: verum
end;
hence u' in {(EmptyBag n),1bag} ; :: thesis: verum
end;
then A14: Support p = {(EmptyBag n),1bag} by A10, TARSKI:2;
then reconsider p = p as Polynomial of n,L by POLYNOM1:def 10;
reconsider p = p as non-zero Polynomial of n,L by A6, POLYNOM7:def 2;
set q = ((0. L) | n,L) +* 1bag,(1. L);
reconsider q = ((0. L) | n,L) +* 1bag,(1. L) as Function of Bags n,L ;
reconsider q = q as Series of n,L ;
dom ((0. L) | n,L) = Bags n by FUNCT_2:def 1;
then A15: q . 1bag = 1. L by FUNCT_7:33;
then A16: q <> 0_ n,L by POLYNOM1:81;
A17: q . (EmptyBag n) = ((0. L) | n,L) . (EmptyBag n) by A2, FUNCT_7:34
.= (0_ n,L) . (EmptyBag n) by POLYNOM7:19
.= 0. L by POLYNOM1:81 ;
A18: now
let u be bag of n; :: thesis: ( u <> 1bag implies q . u = 0. L )
assume u <> 1bag ; :: thesis: q . u = 0. L
then q . u = ((0. L) | n,L) . u by FUNCT_7:34;
then q . u = (0_ n,L) . u by POLYNOM7:19;
hence q . u = 0. L by POLYNOM1:81; :: thesis: verum
end;
A19: now
let u be set ; :: thesis: ( u in {1bag} implies u in Support q )
assume u in {1bag} ; :: thesis: u in Support q
then u = 1bag by TARSKI:def 1;
hence u in Support q by A15, POLYNOM1:def 9; :: thesis: verum
end;
now
let u' be set ; :: thesis: ( u' in Support q implies u' in {1bag} )
assume A20: u' in Support q ; :: thesis: u' in {1bag}
then reconsider u = u' as Element of Bags n ;
A21: q . u <> 0. L by A20, POLYNOM1:def 9;
now end;
hence u' in {1bag} ; :: thesis: verum
end;
then A22: Support q = {1bag} by A19, TARSKI:2;
then reconsider q = q as Polynomial of n,L by POLYNOM1:def 10;
reconsider q = q as non-zero Polynomial of n,L by A16, POLYNOM7:def 2;
Support p <> {} by A6, POLYNOM7:1;
then A23: HT p,T in Support p by TERMORD:def 6;
A24: now end;
then A27: HT p,T = 1bag by A14, A23, TARSKI:def 2;
Support q <> {} by A16, POLYNOM7:1;
then A28: HT q,T in Support q by TERMORD:def 6;
set P = {p,q};
now
let u be set ; :: thesis: ( u in {p,q} implies u in the carrier of (Polynom-Ring n,L) )
assume u in {p,q} ; :: thesis: u in the carrier of (Polynom-Ring n,L)
then ( u = p or u = q ) by TARSKI:def 2;
hence u in the carrier of (Polynom-Ring n,L) by POLYNOM1:def 27; :: thesis: verum
end;
then reconsider P = {p,q} as Subset of (Polynom-Ring n,L) by TARSKI:def 3;
reconsider P = P as Subset of (Polynom-Ring n,L) ;
set R = PolyRedRel P,T;
take P ; :: thesis: not P is_Groebner_basis_wrt T
set p1 = q - (((q . (HT p,T)) / (HC p,T)) * ((EmptyBag n) *' p));
A29: HT p,T in Support q by A22, A27, TARSKI:def 1;
(EmptyBag n) + (HT p,T) = HT p,T by POLYNOM1:57;
then q reduces_to q - (((q . (HT p,T)) / (HC p,T)) * ((EmptyBag n) *' p)),p, HT p,T,T by A6, A16, A29, POLYRED:def 5;
then A30: q reduces_to q - (((q . (HT p,T)) / (HC p,T)) * ((EmptyBag n) *' p)),p,T by POLYRED:def 6;
A31: q - (((q . (HT p,T)) / (HC p,T)) * ((EmptyBag n) *' p)) = q - (((1. L) / (p . 1bag)) * ((EmptyBag n) *' p)) by A15, A27, TERMORD:def 7
.= q - (((1. L) / (1. L)) * ((EmptyBag n) *' p)) by A4, FUNCT_7:33
.= q - (((1. L) * ((1. L) " )) * ((EmptyBag n) *' p)) by VECTSP_1:def 23
.= q - ((1. L) * ((EmptyBag n) *' p)) by VECTSP_1:def 22
.= q - ((1. L) * p) by POLYRED:17
.= q - (((1. L) | n,L) *' p) by POLYNOM7:27
.= q - ((1_ n,L) *' p) by POLYNOM7:20
.= q - p by POLYNOM1:89 ;
p in P by TARSKI:def 2;
then q reduces_to q - p,P,T by A30, A31, POLYRED:def 7;
then A32: [q,(q - p)] in PolyRedRel P,T by POLYRED:def 13;
set q1 = q - (((q . (HT q,T)) / (HC q,T)) * ((EmptyBag n) *' q));
(EmptyBag n) + (HT q,T) = HT q,T by POLYNOM1:57;
then q reduces_to q - (((q . (HT q,T)) / (HC q,T)) * ((EmptyBag n) *' q)),q, HT q,T,T by A16, A28, POLYRED:def 5;
then A33: q reduces_to q - (((q . (HT q,T)) / (HC q,T)) * ((EmptyBag n) *' q)),q,T by POLYRED:def 6;
A34: HC q,T <> 0. L by A16, TERMORD:17;
A35: q - (((q . (HT q,T)) / (HC q,T)) * ((EmptyBag n) *' q)) = q - (((HC q,T) / (HC q,T)) * ((EmptyBag n) *' q)) by TERMORD:def 7
.= q - (((HC q,T) * ((HC q,T) " )) * ((EmptyBag n) *' q)) by VECTSP_1:def 23
.= q - ((1. L) * ((EmptyBag n) *' q)) by A34, VECTSP_1:def 22
.= q - ((1. L) * q) by POLYRED:17
.= q - (((1. L) | n,L) *' q) by POLYNOM7:27
.= q - ((1_ n,L) *' q) by POLYNOM7:20
.= q - q by POLYNOM1:89
.= 0_ n,L by POLYNOM1:83 ;
q in P by TARSKI:def 2;
then q reduces_to 0_ n,L,P,T by A33, A35, POLYRED:def 7;
then A36: [q,(0_ n,L)] in PolyRedRel P,T by POLYRED:def 13;
A37: now end;
A38: now
assume q - p = 0_ n,L ; :: thesis: contradiction
then p = (q - p) + p by POLYRED:2
.= (q + (- p)) + p by POLYNOM1:def 23
.= q + ((- p) + p) by POLYNOM1:80
.= q + (0_ n,L) by POLYRED:3 ;
hence contradiction by A37, POLYNOM1:82; :: thesis: verum
end;
now
assume PolyRedRel P,T is locally-confluent ; :: thesis: contradiction
then 0_ n,L,q - p are_convergent_wrt PolyRedRel P,T by A32, A36, REWRITE1:def 24;
then consider c being set such that
A39: ( PolyRedRel P,T reduces 0_ n,L,c & PolyRedRel P,T reduces q - p,c ) by REWRITE1:def 7;
reconsider c = c as Polynomial of n,L by A39, Lm4;
consider s being FinSequence such that
A40: ( len s > 0 & s . 1 = 0_ n,L & s . (len s) = c & ( for i being Element of NAT st i in dom s & i + 1 in dom s holds
[(s . i),(s . (i + 1))] in PolyRedRel P,T ) ) by A39, REWRITE1:12;
A41: now
assume A42: len s <> 1 ; :: thesis: contradiction
A43: 0 + 1 <= len s by A40, NAT_1:13;
then 1 < len s by A42, XXREAL_0:1;
then A44: 1 + 1 <= len s by NAT_1:13;
A45: dom s = Seg (len s) by FINSEQ_1:def 3;
then A46: 1 in dom s by A43, FINSEQ_1:3;
1 + 1 in dom s by A44, A45, FINSEQ_1:3;
then A47: [(s . 1),(s . 2)] in PolyRedRel P,T by A40, A46;
then consider f', h' being set such that
A48: ( [(0_ n,L),(s . 2)] = [f',h'] & f' in the carrier of (Polynom-Ring n,L) \ {(0_ n,L)} & h' in the carrier of (Polynom-Ring n,L) ) by A40, RELSET_1:6;
s . 2 = [f',h'] `2 by A48, MCART_1:def 2
.= h' by MCART_1:def 2 ;
then reconsider c' = s . 2 as Polynomial of n,L by A48, POLYNOM1:def 27;
0_ n,L reduces_to c',P,T by A40, A47, POLYRED:def 13;
then consider g being Polynomial of n,L such that
A49: ( g in P & 0_ n,L reduces_to c',g,T ) by POLYRED:def 7;
0_ n,L is_reducible_wrt g,T by A49, POLYRED:def 8;
hence contradiction by POLYRED:37; :: thesis: verum
end;
A50: now
assume - (1. L) = 0. L ; :: thesis: contradiction
then - (- (1. L)) = 0. L by RLVECT_1:25;
hence contradiction by RLVECT_1:30; :: thesis: verum
end;
A51: now
let u be set ; :: thesis: ( u in {(EmptyBag n)} implies u in Support (q - p) )
assume A52: u in {(EmptyBag n)} ; :: thesis: u in Support (q - p)
then reconsider u' = u as Element of Bags n by TARSKI:def 1;
(q - p) . u' = (q + (- p)) . u' by POLYNOM1:def 23
.= (q . u') + ((- p) . u') by POLYNOM1:def 21
.= (q . u') + (- (p . u')) by POLYNOM1:def 22
.= (0. L) + (- (p . u')) by A17, A52, TARSKI:def 1
.= (0. L) + (- (1. L)) by A7, A52, TARSKI:def 1
.= - (1. L) by ALGSTR_1:def 5 ;
hence u in Support (q - p) by A50, POLYNOM1:def 9; :: thesis: verum
end;
now
let u be set ; :: thesis: ( u in Support (q - p) implies u in {(EmptyBag n)} )
assume A53: u in Support (q - p) ; :: thesis: u in {(EmptyBag n)}
then A54: (q - p) . u <> 0. L by POLYNOM1:def 9;
Support (q - p) = Support (q + (- p)) by POLYNOM1:def 23;
then Support (q - p) c= (Support q) \/ (Support (- p)) by POLYNOM1:79;
then A55: Support (q - p) c= {1bag} \/ {(EmptyBag n),1bag} by A14, A22, Th5;
now
let u be set ; :: thesis: ( u in {1bag} implies u in {(EmptyBag n),1bag} )
assume u in {1bag} ; :: thesis: u in {(EmptyBag n),1bag}
then u = 1bag by TARSKI:def 1;
hence u in {(EmptyBag n),1bag} by TARSKI:def 2; :: thesis: verum
end;
then {1bag} c= {(EmptyBag n),1bag} by TARSKI:def 3;
then A56: {1bag} \/ {(EmptyBag n),1bag} = {(EmptyBag n),1bag} by XBOOLE_1:12;
(q - p) . 1bag = (q + (- p)) . 1bag by POLYNOM1:def 23
.= (q . 1bag) + ((- p) . 1bag) by POLYNOM1:def 21
.= (q . 1bag) + (- (p . 1bag)) by POLYNOM1:def 22
.= (1. L) + (- (1. L)) by A4, A15, FUNCT_7:33
.= 0. L by RLVECT_1:16 ;
then u = EmptyBag n by A53, A54, A55, A56, TARSKI:def 2;
hence u in {(EmptyBag n)} by TARSKI:def 1; :: thesis: verum
end;
then A57: Support (q - p) = {(EmptyBag n)} by A51, TARSKI:2;
A58: now
assume q - p is_reducible_wrt P,T ; :: thesis: contradiction
then consider g being Polynomial of n,L such that
A59: q - p reduces_to g,P,T by POLYRED:def 9;
consider h being Polynomial of n,L such that
A60: ( h in P & q - p reduces_to g,h,T ) by A59, POLYRED:def 7;
consider b being bag of n such that
A61: q - p reduces_to g,h,b,T by A60, POLYRED:def 6;
( q - p <> 0_ n,L & h <> 0_ n,L & b in Support (q - p) & ex s being bag of n st
( s + (HT h,T) = b & g = (q - p) - ((((q - p) . b) / (HC h,T)) * (s *' h)) ) ) by A61, POLYRED:def 5;
then reconsider h = h as non-zero Polynomial of n,L by POLYNOM7:def 2;
q - p is_reducible_wrt h,T by A60, POLYRED:def 8;
then consider b' being bag of n such that
A62: ( b' in Support (q - p) & HT h,T divides b' ) by POLYRED:36;
A63: b' = EmptyBag n by A57, A62, TARSKI:def 1;
HT h,T = 1bag
proof
now
per cases ( h = p or h = q ) by A60, TARSKI:def 2;
case h = p ; :: thesis: HT h,T = 1bag
hence HT h,T = 1bag by A14, A23, A24, TARSKI:def 2; :: thesis: verum
end;
case h = q ; :: thesis: HT h,T = 1bag
hence HT h,T = 1bag by A22, A28, TARSKI:def 1; :: thesis: verum
end;
end;
end;
hence HT h,T = 1bag ; :: thesis: verum
end;
hence contradiction by A2, A62, A63, POLYNOM1:62; :: thesis: verum
end;
consider s being FinSequence such that
A64: ( len s > 0 & s . 1 = q - p & s . (len s) = 0_ n,L & ( for i being Element of NAT st i in dom s & i + 1 in dom s holds
[(s . i),(s . (i + 1))] in PolyRedRel P,T ) ) by A39, A40, A41, REWRITE1:12;
now
assume A65: len s <> 1 ; :: thesis: contradiction
A66: 0 + 1 <= len s by A64, NAT_1:13;
then 1 < len s by A65, XXREAL_0:1;
then A67: 1 + 1 <= len s by NAT_1:13;
A68: dom s = Seg (len s) by FINSEQ_1:def 3;
then A69: 1 in dom s by A66, FINSEQ_1:3;
1 + 1 in dom s by A67, A68, FINSEQ_1:3;
then A70: [(q - p),(s . 2)] in PolyRedRel P,T by A64, A69;
then consider f', h' being set such that
A71: ( [(q - p),(s . 2)] = [f',h'] & f' in the carrier of (Polynom-Ring n,L) \ {(0_ n,L)} & h' in the carrier of (Polynom-Ring n,L) ) by RELSET_1:6;
s . 2 = [f',h'] `2 by A71, MCART_1:def 2
.= h' by MCART_1:def 2 ;
then reconsider c' = s . 2 as Polynomial of n,L by A71, POLYNOM1:def 27;
q - p reduces_to c',P,T by A70, POLYRED:def 13;
hence contradiction by A58, POLYRED:def 9; :: thesis: verum
end;
hence contradiction by A38, A64; :: thesis: verum
end;
hence not P is_Groebner_basis_wrt T by Def3; :: thesis: verum