How to prove it?

(Anonymous)

Proof by example: The author gives only the case n = 2 and suggests that it contains most of the ideas of the general proof.
Proof by intimidation: 'Trivial'.
Proof by vigorous handwaving: Works well in a classroom or seminar setting.
Proof by cumbersome notation: Best done with access to at least four alphabets and special symbols.
Proof by exhaustion: An issue or two of a journal devoted to your proof is useful.
Proof by omission: 'The reader may easily supply the details'; 'The other 253 cases are analogous'; '...'
Proof by obfuscation: A long plotless sequence of true and/or meaningless syntactically related statements.
Proof by wishful citation: The author cites the negation, converse, or generalization of a theorem from the literature to support his claims.
Proof by funding: How could three different government agencies be wrong?
Proof by eminent authority: 'I saw Karp in the elevator and he said it was probably NP- complete.'
Proof by personal communication: 'Eight-dimensional colored cycle stripping is NP-complete [Karp, personal communication].'
Proof by reduction to the wrong problem: 'To see that infinite-dimensional colored cycle stripping is decidable, we reduce it to the halting problem.'
Proof by reference to inaccessible literature: The author cites a simple corollary of a theorem to be found in a privately circulated memoir of the Slovenian Philological Society, 1883.
Proof by importance: A large body of useful consequences all follow from the proposition in question.
Proof by accumulated evidence: Long and diligent search has not revealed a counterexample.
Proof by cosmology: The negation of the proposition is unimaginable or meaningless. Popular for proofs of the existence of God.
Proof by mutual reference: In reference A, Theorem 5 is said to follow from Theorem 3 in reference B, which is shown to follow from Corollary 6.2 in reference C, which is an easy consequence of Theorem 5 in reference A.
Proof by metaproof: A method is given to construct the desired proof. The correctness of the method is proved by any of these techniques.
Proof by picture: A more convincing form of proof by example. Combines well with proof by omission.
Proof by vehement assertion: It is useful to have some kind of authority relation to the audience.
Proof by ghost reference: Nothing even remotely resembling the cited theorem appears in the reference given.
Proof by forward reference: Reference is usually to a forthcoming paper of the author, which is often not as forthcoming as at first.
Proof by semantic shift: Some of the standard but inconvenient definitions are changed for the statement of the result.
Proof by appeal to intuition: Cloud-shaped drawings frequently help here.