set R = INT.Ring ;
set K = Polynom-Ring INT.Ring;
set a = (1. INT.Ring) + (1. INT.Ring);
set p = (((1. INT.Ring) + (1. INT.Ring)) | INT.Ring) *' (rpoly (1,(0. INT.Ring)));
(1. INT.Ring) + (1. INT.Ring) <> 0. INT.Ring
;
then reconsider a = (1. INT.Ring) + (1. INT.Ring) as non zero Element of INT.Ring by STRUCT_0:def 12;
reconsider q = a | INT.Ring as Element of the carrier of (Polynom-Ring INT.Ring) by POLYNOM3:def 10;
q is constant
by RATFUNC1:def 2;
then reconsider q = q as non zero constant Element of the carrier of (Polynom-Ring INT.Ring) ;
reconsider r = rpoly (1,(0. INT.Ring)) as Element of the carrier of (Polynom-Ring INT.Ring) by POLYNOM3:def 10;
A1: (((1. INT.Ring) + (1. INT.Ring)) | INT.Ring) *' (rpoly (1,(0. INT.Ring))) =
(a * (1_. INT.Ring)) *' (rpoly (1,(0. INT.Ring)))
by LX1
.=
a * ((1_. INT.Ring) *' (rpoly (1,(0. INT.Ring))))
by poly2
.=
a * (rpoly (1,(0. INT.Ring)))
by poly1
;
A2: deg ((((1. INT.Ring) + (1. INT.Ring)) | INT.Ring) *' (rpoly (1,(0. INT.Ring)))) =
(deg q) + (deg (rpoly (1,(0. INT.Ring))))
by HURWITZ:23
.=
0 + (deg (rpoly (1,(0. INT.Ring))))
by LX
.=
1
by HURWITZ:27
;
then ((((1. INT.Ring) + (1. INT.Ring)) | INT.Ring) *' (rpoly (1,(0. INT.Ring)))) . ((len ((((1. INT.Ring) + (1. INT.Ring)) | INT.Ring) *' (rpoly (1,(0. INT.Ring))))) -' 1) =
(a * (rpoly (1,(0. INT.Ring)))) . (2 - 1)
by A1, XREAL_1:233
.=
a * ((rpoly (1,(0. INT.Ring))) . 1)
by POLYNOM5:def 4
.=
a * (1. INT.Ring)
by HURWITZ:25
.=
a
;
then
LC ((((1. INT.Ring) + (1. INT.Ring)) | INT.Ring) *' (rpoly (1,(0. INT.Ring)))) = a
;
then reconsider pp = (((1. INT.Ring) + (1. INT.Ring)) | INT.Ring) *' (rpoly (1,(0. INT.Ring))) as non monic Element of the carrier of (Polynom-Ring INT.Ring) by RATFUNC1:def 7, POLYNOM3:def 10;
take
pp
; ( deg pp = 1 & pp is reducible )
thus
deg pp = 1
by A2; pp is reducible
B0:
(((1. INT.Ring) + (1. INT.Ring)) | INT.Ring) *' (rpoly (1,(0. INT.Ring))) = q * r
by POLYNOM3:def 10;
B1:
q divides pp
by B0, GCD_1:def 1;
hence
pp is reducible
by B1, B4, RING_2:def 9; verum