Summary

Additional properties of binary relations

antisymmetric -> the only two-way relations are self-loops
totality -> every element is related to every other element in at least one way

Partial order

  • a relation that is reflexive, antisymmetric and transitive

Total order

  • a partial order that is total

Concept

Bounded below

Well-ordering principle for integers

  • basis for proof by induction
  • in a totally ordered set, that is bounded below by some integer, there is a smallest integer

Proving properties

Application

Well-ordering does not apply to all sets