Ordinal Arithmetic

Basic Ordinal and Cardinal Arithmetic II

Basic Ordinal and Cardinal Arithmetic II

Mike
We prove more results for Ordinal and Cardinal arithmetic. Including showing that we can apply division with remainders to ordinals. We use that to prove Cantor’s Normal Form Theorem. Finally, we give a proof of Konig’s Theorem for Cardinals.
Basic Ordinal and Cardinal Arithmetic

Basic Ordinal and Cardinal Arithmetic

Mike
In this entry we cover more basic results about ordinal arithmetic. We also prove the so-called “Fundamental Theorem of Cardinal Arithmetic”, and then we finish with a short discussion about cofinality of cardinals.
An Intro to Sets III

An Intro to Sets III

Mike
Here we dig into ordinal and cardinal arithmetic a little bit. We also establish the famous result (originally due to Cantor) that |S| < |P(S)|, i.e. that the power set of any set is larger than the set.