let p be INT -valued Polynomial of F_Real; :: thesis: for e being Element of F_Real st e is_a_root_of p holds
for k, l being Integer st l <> 0 & e = k / l & k,l are_coprime holds
( k divides p . 0 & l divides LC p )

let e be Element of F_Real; :: thesis: ( e is_a_root_of p implies for k, l being Integer st l <> 0 & e = k / l & k,l are_coprime holds
( k divides p . 0 & l divides LC p ) )

assume A1: e is_a_root_of p ; :: thesis: for k, l being Integer st l <> 0 & e = k / l & k,l are_coprime holds
( k divides p . 0 & l divides LC p )

let k, l be Integer; :: thesis: ( l <> 0 & e = k / l & k,l are_coprime implies ( k divides p . 0 & l divides LC p ) )
assume A2: ( l <> 0 & e = k / l & k,l are_coprime ) ; :: thesis: ( k divides p . 0 & l divides LC p )
consider F being FinSequence of F_Real such that
A3: ( 0. F_Real = Sum F & len F = len p & ( for n being Element of NAT st n in dom F holds
F . n = (p . (n -' 1)) * ((power F_Real) . (e,(n -' 1))) ) ) by A1, POLYNOM4:def 2;
per cases ( len F = 0 or len F > 0 ) ;
suppose len F = 0 ; :: thesis: ( k divides p . 0 & l divides LC p )
end;
suppose A5: len F > 0 ; :: thesis: ( k divides p . 0 & l divides LC p )
set n = len p;
A6: len p >= 1 by A5, A3, NAT_1:14;
reconsider n1 = (len p) - 1 as Element of NAT by NAT_1:20, A5, A3;
A7: (len p) -' 1 = n1 by A5, A3, NAT_1:14, XREAL_1:233;
A8: l |^ ((len p) -' 1) <> 0 by A2, CARD_4:3;
reconsider k1 = k, l1 = l as Element of F_Real by XREAL_0:def 1;
set ln = (power F_Real) . (l1,n1);
set G = ((power F_Real) . (l1,n1)) * F;
reconsider FF = F as Element of (len F) -tuples_on the carrier of F_Real by FINSEQ_2:92;
set GG = ((power F_Real) . (l1,n1)) * FF;
A9: len (((power F_Real) . (l1,n1)) * FF) = len F by FINSEQ_2:132;
then A10: dom (((power F_Real) . (l1,n1)) * F) = dom F by FINSEQ_3:29;
A11: Sum (((power F_Real) . (l1,n1)) * F) = ((power F_Real) . (l1,n1)) * (Sum F) by FVSUM_1:73;
rng (((power F_Real) . (l1,n1)) * F) c= INT
proof
let o be object ; :: according to TARSKI:def 3 :: thesis: ( not o in rng (((power F_Real) . (l1,n1)) * F) or o in INT )
assume o in rng (((power F_Real) . (l1,n1)) * F) ; :: thesis: o in INT
then consider b being object such that
A12: ( b in dom (((power F_Real) . (l1,n1)) * F) & o = (((power F_Real) . (l1,n1)) * F) . b ) by FUNCT_1:def 3;
reconsider b = b as Element of NAT by A12;
b in Seg (len p) by A12, A9, A3, FINSEQ_1:def 3;
then ( 1 <= b & b <= len p & b -' 1 <= b ) by FINSEQ_1:1, NAT_D:35;
then ( b -' 1 = b - 1 & b - 1 <= n1 ) by XREAL_1:233, XREAL_1:9;
then consider c being Nat such that
A13: n1 = (b -' 1) + c by NAT_1:10;
rng F c= the carrier of F_Real ;
then reconsider a9 = F . b as Element of F_Real by A12, A10, FUNCT_1:3;
A14: l |^ (b -' 1) <> 0 by A2, CARD_4:3;
( b in dom (((power F_Real) . (l1,n1)) * F) & a9 = F . b implies (((power F_Real) . (l1,n1)) * F) . b = ((power F_Real) . (l1,n1)) * a9 ) by FVSUM_1:50;
then (((power F_Real) . (l1,n1)) * F) . b = ((power F_Real) . (l1,n1)) * ((p . (b -' 1)) * ((power F_Real) . (e,(b -' 1)))) by A3, A12, A10
.= (p . (b -' 1)) * (((power F_Real) . (l1,n1)) * ((power F_Real) . (e,(b -' 1))))
.= (p . (b -' 1)) * ((l1 |^ n1) * ((power F_Real) . (e,(b -' 1)))) by Th48
.= (p . (b -' 1)) * ((l1 |^ n1) * ((k / l) |^ (b -' 1))) by A2, Th48
.= (p . (b -' 1)) * ((l |^ n1) * ((k |^ (b -' 1)) / (l |^ (b -' 1)))) by PREPOWER:8
.= ((p . (b -' 1)) * (k |^ (b -' 1))) * ((l |^ n1) / (l |^ (b -' 1)))
.= ((p . (b -' 1)) * (k |^ (b -' 1))) * (((l |^ c) * (l |^ (b -' 1))) / (l |^ (b -' 1))) by A13, NEWTON:8
.= ((p . (b -' 1)) * (k |^ (b -' 1))) * ((l |^ c) * ((l |^ (b -' 1)) / (l |^ (b -' 1))))
.= ((p . (b -' 1)) * (k |^ (b -' 1))) * ((l |^ c) * 1) by XCMPLX_1:60, A14
.= ((p . (b -' 1)) * (k |^ (b -' 1))) * (l |^ c) ;
hence o in INT by INT_1:def 2, A12; :: thesis: verum
end;
then reconsider G1 = ((power F_Real) . (l1,n1)) * F as INT -valued non empty FinSequence by A9, A5, RELAT_1:def 19;
A15: 1 in dom (((power F_Real) . (l1,n1)) * F) by A9, A6, A3, FINSEQ_3:25;
A16: Sum G1 = Sum (((power F_Real) . (l1,n1)) * F) by Th49;
A17: Sum G1 = 0 by A3, A11, Th49;
reconsider Gn0 = G1 /^ 1 as INT -valued FinSequence ;
((power F_Real) . (l1,n1)) * F = <*((((power F_Real) . (l1,n1)) * F) /. 1)*> ^ Gn0 by FINSEQ_5:29;
then (Sum Gn0) + ((((power F_Real) . (l1,n1)) * F) /. 1) = 0 by RVSUM_1:76, A16, A11, A3;
then (Sum Gn0) + ((((power F_Real) . (l1,n1)) * F) . 1) = 0 by A15, PARTFUN1:def 6;
then A18: Sum Gn0 = - (G1 . 1) ;
rng F c= the carrier of F_Real ;
then reconsider a9 = F . 1 as Element of F_Real by A15, A10, FUNCT_1:3;
A19: G1 . 1 = ((power F_Real) . (l1,n1)) * a9 by FVSUM_1:50, A15
.= ((power F_Real) . (l1,n1)) * ((p . (1 -' 1)) * ((power F_Real) . (e,(1 -' 1)))) by A6, A3, FINSEQ_3:25
.= ((p . (1 -' 1)) * ((power F_Real) . (l1,n1))) * ((power F_Real) . (e,(1 -' 1)))
.= ((p . (1 -' 1)) * ((power F_Real) . (l1,n1))) * ((power F_Real) . (e,0)) by XREAL_1:232
.= ((p . 0) * ((power F_Real) . (l1,n1))) * ((power F_Real) . (e,0)) by XREAL_1:232
.= ((p . 0) * ((power F_Real) . (l1,n1))) * (1_ F_Real) by GROUP_1:def 7
.= (p . 0) * (l |^ n1) by Th48 ;
for i being Nat st i in dom Gn0 holds
k divides Gn0 . i
proof
let i be Nat; :: thesis: ( i in dom Gn0 implies k divides Gn0 . i )
assume A20: i in dom Gn0 ; :: thesis: k divides Gn0 . i
then A21: 1 + i in dom G1 by FINSEQ_5:26;
rng F c= the carrier of F_Real ;
then reconsider a9 = F . (1 + i) as Element of F_Real by A21, A10, FUNCT_1:3;
A22: l |^ i <> 0 by A2, CARD_4:3;
A23: ( 1 <= i & i <= len Gn0 ) by A20, FINSEQ_3:25;
i + 1 in Seg (len p) by A3, A21, A9, FINSEQ_1:def 3;
then i + 1 <= len p by FINSEQ_1:1;
then (i + 1) - 1 <= (len p) - 1 by XREAL_1:9;
then consider d being Nat such that
A24: n1 = i + d by NAT_1:10;
Gn0 . i = ((((power F_Real) . (l1,n1)) * F) /^ 1) /. i by A20, PARTFUN1:def 6
.= (((power F_Real) . (l1,n1)) * F) /. (1 + i) by FINSEQ_5:27, A20
.= (((power F_Real) . (l1,n1)) * F) . (1 + i) by A21, PARTFUN1:def 6
.= ((power F_Real) . (l1,n1)) * a9 by FVSUM_1:50, A21
.= ((power F_Real) . (l1,n1)) * ((p . ((1 + i) -' 1)) * ((power F_Real) . (e,((1 + i) -' 1)))) by A3, A21, A10
.= ((power F_Real) . (l1,n1)) * ((p . i) * ((power F_Real) . (e,((1 + i) -' 1)))) by NAT_D:34
.= ((power F_Real) . (l1,n1)) * ((p . i) * ((power F_Real) . (e,i))) by NAT_D:34
.= (p . i) * (((power F_Real) . (l1,n1)) * ((power F_Real) . (e,i)))
.= (p . i) * ((l1 |^ n1) * ((power F_Real) . (e,i))) by Th48
.= (p . i) * ((l1 |^ n1) * (e |^ i)) by Th48
.= (p . i) * ((l |^ n1) * ((k |^ i) / (l |^ i))) by A2, PREPOWER:8
.= ((p . i) * (k |^ i)) * ((l |^ (d + i)) / (l |^ i)) by A24
.= ((p . i) * (k |^ i)) * (((l |^ d) * (l |^ i)) / (l |^ i)) by NEWTON:8
.= ((p . i) * (k |^ i)) * ((l |^ d) * ((l |^ i) / (l |^ i)))
.= ((p . i) * (k |^ i)) * ((l |^ d) * 1) by XCMPLX_1:60, A22
.= ((p . i) * (l |^ d)) * (k |^ i) ;
hence k divides Gn0 . i by A23, Th4, INT_2:2; :: thesis: verum
end;
then k divides G1 . 1 by A18, NEWTON04:80, INT_2:10;
hence k divides p . 0 by A19, A2, WSIERP_1:10, INT_2:25; :: thesis: l divides LC p
reconsider Gn1 = G1 | (Seg n1) as INT -valued FinSequence by FINSEQ_1:15;
A25: len (((power F_Real) . (l1,n1)) * FF) = len F by FINSEQ_2:132;
then A26: len G1 = n1 + 1 by A3;
G1 = Gn1 ^ <*(G1 . (n1 + 1))*> by A25, A3, FINSEQ_3:55;
then (Sum Gn1) + (G1 . (n1 + 1)) = 0 by RVSUM_1:74, A17;
then A27: Sum Gn1 = - (G1 . (n1 + 1))
.= - (G1 . (len p)) ;
A28: len p in dom F by FINSEQ_3:25, A6, A3;
rng F c= the carrier of F_Real ;
then reconsider a9 = F . (len p) as Element of F_Real by A28, FUNCT_1:3;
len p in dom G1 by A25, A3, FINSEQ_3:25, A6;
then A29: G1 . (len p) = ((power F_Real) . (l1,n1)) * a9 by FVSUM_1:50
.= ((power F_Real) . (l1,n1)) * ((p . ((len p) -' 1)) * ((power F_Real) . (e,((len p) -' 1)))) by A6, A3, FINSEQ_3:25
.= (p . ((len p) -' 1)) * (((power F_Real) . (l1,n1)) * ((power F_Real) . (e,((len p) -' 1))))
.= (p . ((len p) -' 1)) * ((l1 |^ n1) * ((power F_Real) . (e,((len p) -' 1)))) by Th48
.= (p . ((len p) -' 1)) * ((l1 |^ n1) * (e |^ ((len p) -' 1))) by Th48
.= (p . ((len p) -' 1)) * ((l |^ n1) * ((k |^ ((len p) -' 1)) / (l |^ ((len p) -' 1)))) by A2, PREPOWER:8
.= ((p . ((len p) -' 1)) * (k |^ ((len p) -' 1))) * ((l |^ ((len p) -' 1)) / (l |^ ((len p) -' 1))) by A7
.= ((p . ((len p) -' 1)) * (k |^ ((len p) -' 1))) * 1 by A8, XCMPLX_1:60
.= (LC p) * (k |^ ((len p) -' 1)) ;
for i being Nat st i in dom Gn1 holds
l divides Gn1 . i
proof
let i be Nat; :: thesis: ( i in dom Gn1 implies l divides Gn1 . i )
assume A30: i in dom Gn1 ; :: thesis: l divides Gn1 . i
then i in Seg n1 by A26, FINSEQ_3:54;
then A31: ( 1 <= i & i <= n1 & i -' 1 <= i ) by FINSEQ_1:1, NAT_D:35;
then consider d being Nat such that
A32: n1 = (i -' 1) + d by XXREAL_0:2, NAT_1:10;
i - i <= ((len p) - 1) - i by A31, XREAL_1:9;
then A33: 0 + 1 <= (((len p) - i) - 1) + 1 by XREAL_1:6;
A34: (len p) - 1 = (i - 1) + d by A32, A31, XREAL_1:233;
A35: Gn1 . i = G1 . i by A30, FUNCT_1:47;
A36: dom Gn1 c= dom G1 by RELAT_1:60;
rng F c= the carrier of F_Real ;
then reconsider a9 = F . i as Element of F_Real by A36, A10, A30, FUNCT_1:3;
A37: l |^ (i -' 1) <> 0 by A2, CARD_4:3;
G1 . i = ((power F_Real) . (l1,n1)) * a9 by A36, A30, FVSUM_1:50
.= ((power F_Real) . (l1,n1)) * ((p . (i -' 1)) * ((power F_Real) . (e,(i -' 1)))) by A3, A36, A30, A10
.= (p . (i -' 1)) * (((power F_Real) . (l1,n1)) * ((power F_Real) . (e,(i -' 1))))
.= (p . (i -' 1)) * ((l1 |^ n1) * ((power F_Real) . (e,(i -' 1)))) by Th48
.= (p . (i -' 1)) * ((l1 |^ n1) * (e |^ (i -' 1))) by Th48
.= (p . (i -' 1)) * ((l |^ n1) * ((k |^ (i -' 1)) / (l |^ (i -' 1)))) by A2, PREPOWER:8
.= ((p . (i -' 1)) * (k |^ (i -' 1))) * ((l |^ n1) / (l |^ (i -' 1)))
.= ((p . (i -' 1)) * (k |^ (i -' 1))) * (((l |^ d) * (l |^ (i -' 1))) / (l |^ (i -' 1))) by A32, NEWTON:8
.= ((p . (i -' 1)) * (k |^ (i -' 1))) * ((l |^ d) * ((l |^ (i -' 1)) / (l |^ (i -' 1))))
.= ((p . (i -' 1)) * (k |^ (i -' 1))) * ((l |^ d) * 1) by XCMPLX_1:60, A37
.= ((p . (i -' 1)) * (k |^ (i -' 1))) * (l |^ d) ;
hence l divides Gn1 . i by A35, A34, A33, Th4, INT_2:2; :: thesis: verum
end;
then l divides G1 . (len p) by A27, NEWTON04:80, INT_2:10;
hence l divides LC p by A29, A2, WSIERP_1:10, INT_2:25; :: thesis: verum
end;
end;