Let $\alpha \in P_R$ be a cut. Since there exists a cut that is not $\{q\in Q\mid q
Let $$\gamma= 0^* \cup \{0\} \cup \{q\in P_Q\mid\text{ there exists }r\in P_Q\text{ such that }r>q\text{ and }1/r \notin \alpha\}\;.$$
I have proved that $\alpha \gamma$ is a subset of $1^*$. I dont't know how to prove $1^*$ is a subset of $\alpha \gamma$. Help
and $0 such that $p≦st$} – 2012-06-11