Logic 101 (#46): Proof By Cases (Killer Proof Strategy #3)

Logic 101

This lecture introduces the proof strategy known as proof by cases. It exploits a setup with two implications featuring the same consequent and a disjunction featuring the antecedents of those implications. With that information, it is easy to conclude that the consequent is true.

In practice, the hard part of proof by cases is usually setting up the implications. This lecture gives an example where using conditional proofs can solve that problem.