set f = rpoly (1,(0. F_Complex));
set p = [(rpoly (1,(0. F_Complex))),(1_. F_Complex)];
take
[(rpoly (1,(0. F_Complex))),(1_. F_Complex)]
; ( not [(rpoly (1,(0. F_Complex))),(1_. F_Complex)] is zero & [(rpoly (1,(0. F_Complex))),(1_. F_Complex)] is odd & [(rpoly (1,(0. F_Complex))),(1_. F_Complex)] is real & [(rpoly (1,(0. F_Complex))),(1_. F_Complex)] is positive )
thus
not [(rpoly (1,(0. F_Complex))),(1_. F_Complex)] is zero
; ( [(rpoly (1,(0. F_Complex))),(1_. F_Complex)] is odd & [(rpoly (1,(0. F_Complex))),(1_. F_Complex)] is real & [(rpoly (1,(0. F_Complex))),(1_. F_Complex)] is positive )
set fp = Polynomial-Function (F_Complex,(rpoly (1,(0. F_Complex))));
now for x being Element of F_Complex holds (Polynomial-Function (F_Complex,(rpoly (1,(0. F_Complex))))) . (- x) = - ((Polynomial-Function (F_Complex,(rpoly (1,(0. F_Complex))))) . x)let x be
Element of
F_Complex;
(Polynomial-Function (F_Complex,(rpoly (1,(0. F_Complex))))) . (- x) = - ((Polynomial-Function (F_Complex,(rpoly (1,(0. F_Complex))))) . x)thus (Polynomial-Function (F_Complex,(rpoly (1,(0. F_Complex))))) . (- x) =
eval (
(rpoly (1,(0. F_Complex))),
(- x))
by POLYNOM5:def 13
.=
(- x) - (0. F_Complex)
by HURWITZ:29
.=
- x
by RLVECT_1:13
.=
- (x - (0. F_Complex))
by RLVECT_1:13
.=
- (eval ((rpoly (1,(0. F_Complex))),x))
by HURWITZ:29
.=
- ((Polynomial-Function (F_Complex,(rpoly (1,(0. F_Complex))))) . x)
by POLYNOM5:def 13
;
verum end;
then
Polynomial-Function (F_Complex,(rpoly (1,(0. F_Complex)))) is odd
;
then
rpoly (1,(0. F_Complex)) is odd
;
hence
[(rpoly (1,(0. F_Complex))),(1_. F_Complex)] is odd
; ( [(rpoly (1,(0. F_Complex))),(1_. F_Complex)] is real & [(rpoly (1,(0. F_Complex))),(1_. F_Complex)] is positive )
reconsider z = 0 as Element of NAT by ORDINAL1:def 12;
now for i being Nat holds
( ([(rpoly (1,(0. F_Complex))),(1_. F_Complex)] `1) . i is Real & ([(rpoly (1,(0. F_Complex))),(1_. F_Complex)] `2) . i is Real )let i be
Nat;
( ([(rpoly (1,(0. F_Complex))),(1_. F_Complex)] `1) . i is Real & ([(rpoly (1,(0. F_Complex))),(1_. F_Complex)] `2) . i is Real )A2:
i in NAT
by ORDINAL1:def 12;
hence
([(rpoly (1,(0. F_Complex))),(1_. F_Complex)] `1) . i is
Real
;
([(rpoly (1,(0. F_Complex))),(1_. F_Complex)] `2) . i is Realthus
([(rpoly (1,(0. F_Complex))),(1_. F_Complex)] `2) . i is
Real
;
verum end;
hence
[(rpoly (1,(0. F_Complex))),(1_. F_Complex)] is real
; [(rpoly (1,(0. F_Complex))),(1_. F_Complex)] is positive
now for x being Element of F_Complex st Re x > 0 & eval (([(rpoly (1,(0. F_Complex))),(1_. F_Complex)] `2),x) <> 0 holds
Re (eval ([(rpoly (1,(0. F_Complex))),(1_. F_Complex)],x)) > 0 let x be
Element of
F_Complex;
( Re x > 0 & eval (([(rpoly (1,(0. F_Complex))),(1_. F_Complex)] `2),x) <> 0 implies Re (eval ([(rpoly (1,(0. F_Complex))),(1_. F_Complex)],x)) > 0 )assume A5:
(
Re x > 0 &
eval (
([(rpoly (1,(0. F_Complex))),(1_. F_Complex)] `2),
x)
<> 0 )
;
Re (eval ([(rpoly (1,(0. F_Complex))),(1_. F_Complex)],x)) > 0 A6:
eval (
(1_. F_Complex),
x)
= 1_ F_Complex
by POLYNOM4:18;
1. F_Complex <> 0. F_Complex
;
then A7:
((1. F_Complex) ") * (1. F_Complex) = 1. F_Complex
by VECTSP_1:def 10;
eval (
[(rpoly (1,(0. F_Complex))),(1_. F_Complex)],
x) =
x * ((1. F_Complex) ")
by A1, A6
.=
x * (1. F_Complex)
by A7
.=
x
;
hence
Re (eval ([(rpoly (1,(0. F_Complex))),(1_. F_Complex)],x)) > 0
by A5;
verum end;
hence
[(rpoly (1,(0. F_Complex))),(1_. F_Complex)] is positive
; verum