Complex sentence: For example, there are reflection principles that imply the existence of and I3 rank-into-rank cardinals, which are among the cardinals with greatest consistency strength whose existence is believed to be consistent with ZFC.
Split into simpler sentences: For example, there are reflection principles that imply the existence of and I3 rank-into-rank cardinals. These are among the cardinals having the greatest consistency strength and whose existence is believed to be consistent with ZFC.