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

theorem Th10:
  i / m = (i div (i gcd m)) / (m div (i gcd m))
  proof
    i gcd m divides i & i gcd m divides m by INT_2:def 2;
    hence thesis by Th9;
  end;
