Diamond principle
= Diamond principle
{title2=$\diamondsuit$}
A sequence $D_\alpha\subseteq\alpha$ guesses every $X\subseteq\omega_1$ stationarily often: $\{\alpha:D_\alpha=X\cap\alpha\}$ is stationary.
= Diamond principle
{title2=$\diamondsuit$}
A sequence $D_\alpha\subseteq\alpha$ guesses every $X\subseteq\omega_1$ stationarily often: $\{\alpha:D_\alpha=X\cap\alpha\}$ is stationary.