set K = FAdj (F_Rat,{3-CRoot(2)});
the carrier of (Polynom-Ring F_Rat) c= the carrier of (Polynom-Ring (FAdj (F_Rat,{3-CRoot(2)}))) by FIELD_4:10;
then reconsider p = X^2+X+1 as Element of the carrier of (Polynom-Ring (FAdj (F_Rat,{3-CRoot(2)}))) ;
A: FAdj (F_Rat,{3-CRoot(2),zeta}) = FAdj (F_Rat,({3-CRoot(2)} \/ {zeta})) by ENUMSET1:1
.= FAdj ((FAdj (F_Rat,{3-CRoot(2)})),{zeta}) by FIELD_7:35 ;
deg p = 2 by LL, FIELD_4:20;
hence deg ((FAdj (F_Rat,{3-CRoot(2),zeta})),(FAdj (F_Rat,{3-CRoot(2)}))) = 2 by A, mmm, FIELD_6:67; :: thesis: verum