There is a feeling that Turing's halting problem, Gödel's incompleteness theorem, the liar paradox, and Cantor's diagonalization theorem are all very similar. They are all talking about limitations of self-referential systems. We shall formulize this feeling by giving a single scheme in which all of the above diverse theorems are instances of that scheme. We shall go through the scheme at tutorial pace and then show the diversity of instances of that scheme.
Colloquia Series page.