reserve p,q for Rational;
reserve g,m,m1,m2,n,n1,n2 for Nat;
reserve i,i1,i2,j,j1,j2 for Integer;
reserve R for Ring, F for Field;

theorem
for E being Field, F being Subfield of E holds PrimeField F = PrimeField E
proof
let E be Field, F be Subfield of E;
PrimeField F is Subfield of E by EC_PF_1:5;
then PrimeField E is Subfield of PrimeField F by Th92;
hence thesis by Th91;
end;
