
theorem
  for a,b be positive Real st a > b holds log (a/b, a) > log (a/b, b)
  proof
    let a,b be positive Real;
    assume
    A1: a > b; then
    a/b > b/b by XREAL_1:68; then
    a/b > 1 by XCMPLX_1:60;
    hence thesis by A1,POWER:57;
  end;
