Diagonal argument

A diagonal argument, in mathematics, is a technique employed in proofs. The following theorems are notable examples:

• Cantor's diagonal argument (the earliest)
• Cantor's theorem
• Russell's paradox
• Diagonal lemma
• Gödel's first incompleteness theorem
• Tarski's undefinability theorem
• Halting problem
• Kleene's recursion theorem

See also

• Diagonalization (disambiguation)