let n be Nat; for F being Field
for E being FieldExtension of F
for x being Function of n,E holds 0. E in rng (hom_Ext_eval (x,F))
let F be Field; for E being FieldExtension of F
for x being Function of n,E holds 0. E in rng (hom_Ext_eval (x,F))
let E be FieldExtension of F; for x being Function of n,E holds 0. E in rng (hom_Ext_eval (x,F))
let x be Function of n,E; 0. E in rng (hom_Ext_eval (x,F))
set f = hom_Ext_eval (x,F);
A:
(hom_Ext_eval (x,F)) . (0. (Polynom-Ring (n,F))) = 0. E
by RING_2:6;
dom (hom_Ext_eval (x,F)) = the carrier of (Polynom-Ring (n,F))
by FUNCT_2:def 1;
hence
0. E in rng (hom_Ext_eval (x,F))
by A, FUNCT_1:def 3; verum