"How to prove it" joke
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.
A young woman goes into the doctor's office for a checkup. As she takes off her blouse, he notices a red "H" on her chest. "How did you get that mark on your chest?" asks the doctor. "Oh, my boyfriend went to Harvard and he's so proud of it that he never more...
A very attractive lady goes up to a bar in a quiet rural pub. She gestures alluringly to the bartender who comes over immediately. When he arrives, she seductively signals that he should bring his face closer to hers. When he does, she begins to gently caress his full more...
Knowledge is knowing a tomato is a fruit; Wisdom is not putting it in a fruit salad.
A mother had 3 virgin daughters. They were all getting married within a short time period. Because Mom was a bit worried about how their sex life would get started, she made them all promise to send a postcard from the honeymoon with a few words on how marital sex felt.
The more...