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 Th88:
for R being Ring, S being Subring of R holds Char S = Char R
proof
let R be Ring, S be Subring of R;
R is S-monomorphic by Th70;
hence thesis by Th87;
end;
