My favorite tactics

[BaalChatzaf]

The most direct form of inference is modus ponens. That is: from P and

P -> Q infer Q. Completely equivalent (in classical logic) is modus tollens; that is from ~Q and P -> Q infer ~P. This is the basis of the indirect proof or proof by reductio ad falsi (or reductio ad absurdum). Ayn Rand apparently like this kind of proof. She was always urging folks to check their premises. If one deduced a false statement or an absurdity, one or more of the premises was false.

When I tackle a math problem I prefer the indirect or flank attack. Hit the problem where least expected. I don't solve problems - I ambush them.

Ba'al Chatzaf