Mu

character (Greek letter).

1. unit /micro/ prefix denoting division by 10^6, e.g. mu m

(micrometre, a millionth part of a metre). Sometimes written

as a 'u', the ASCII character nearest in appearance.

2. mathematics /myoo/ In the theory of functions, mu x . E

denotes the least value of x for which E = x, i.e. the leastfixed point of the function x . E. The recursive

function mu f . H f satisfies (and is defined by) the equation

mu f . H f = H (mu f . H f)

An alternative notation for the same function is

fix H = H (fix H)

See fixed point combinator.

3. database multiple value.

[Jargon File]

(1995-10-30)