
theorem lift6b:
for F1,F2 being Field
st F1 == F2 holds 0_.(F1) = 0_.(F2) & 1_.(F1) = 1_.(F2)
proof
let F1,F2 be Field;
assume F1 == F2; then
   F1 is Subfield of F2 by FIELD_7:def 2; then
A: F2 is FieldExtension of F1 by FIELD_4:7;
hence 0_.(F1) = 0_.(F2) by FIELD_4:12;
thus 1_.(F1) = 1_.(F2) by A,FIELD_4:14;
end;
