1.
mathematics A
set containing a certain number of
objects selected from another set.
The number of combinations of r objects chosen from a set of n
is
n C r = n! / ((n-r)! r!)
where "n C r" is normally with n and r as subscripts or as n
above r in parentheses.
2.
reduction In the theory of
combinators, a combination
only operation.
(1995-04-10)