A: X_ *' X-1 = (rpoly (1,(- (0. (Z/ 2))))) *' <%(1. (Z/ 2)),(- (- (1. (Z/ 2))))%> by RING_5:10
.= (rpoly (1,(0. (Z/ 2)))) *' (rpoly (1,(1. (Z/ 2)))) by cz2a, RING_5:10 ;
hence B: X_ *' X-1 = <%((0. (Z/ 2)) * (1. (Z/ 2))),(- ((0. (Z/ 2)) + (1. (Z/ 2)))),(1. (Z/ 2))%> by lemred3z
.= X^2+X by FIELD_3:4, RLVECT_1:def 10 ;
:: thesis: Roots X^2+X = {(0. (Z/ 2)),(1. (Z/ 2))}
( Roots (rpoly (1,(1. (Z/ 2)))) = {(1. (Z/ 2))} & Roots (rpoly (1,(0. (Z/ 2)))) = {(0. (Z/ 2))} ) by RING_5:18;
then Roots ((rpoly (1,(0. (Z/ 2)))) *' (rpoly (1,(1. (Z/ 2))))) = {(0. (Z/ 2))} \/ {(1. (Z/ 2))} by UPROOTS:23
.= {(0. (Z/ 2)),(1. (Z/ 2))} by ENUMSET1:1 ;
hence Roots X^2+X = {(0. (Z/ 2)),(1. (Z/ 2))} by A, B; :: thesis: verum