persuasion

n 1: the act of persuading (or attempting to persuade) [syn: {suasion}]

2: a personal belief that is not founded on proof or certainty;

"my opinion differs from yours"; "what are your thoughts

on Haiti?" [syn: {opinion}, {sentiment}, {view}, {thought}]

3: inducement by argument or reasoning or entreaty [ant: {dissuasion}]

4: changing a person's beliefs by argument or reasoning or

entreaty

permutation

An ordering of a certain number of elements of a

given set.

For instance, the permutations of (1,2,3) are (1,2,3) (2,3,1)

(3,1,2) (3,2,1) (1,3,2) (2,1,3).

Permutations form one of the canonical examples of a "{group}"

- they can be composed and that you can find an inverse

permutation that reverses the action of any given permutation.

A permutation is a {bijection}.

The number of permutations of r things taken from a set of n

is

n P r ◦ n! / (n-r)!

where "n P r" is usually written with n and r as subscripts

and n! is the {factorial} of n.

What the football pools call a "permutation" is not a

permutation but a {combination} - the order does not matter.

(1995-04-10)