(*#* The second version of the density of [Q] in [R1] states that given
any positive real number, there is a rational number between it and
zero. This lemma can be used to prove the more general fact that there
is a rational number between any two real numbers. *)
(*#* The second version of the density of [Q] in [R1] states that given
any positive real number, there is a rational number between it and
zero. This lemma can be used to prove the more general fact that there
is a rational number between any two real numbers. *)