(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 least fixed 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]

Last updated: 1995-10-30