The Default Random Source
Function: random-integer n
Return a random number between zero (inclusive) and n (exclusive), using the default random source. The numbers returned have a uniform distribution.
Function: random-real
Return a random number in (0,1), using the default random source. The numbers returned have a uniform distribution.
Function: default-random-source
A random source from which random-integer and random-real have been derived using random-source-make-integers and random-source-make-reals (see Obtaining random number generator procedures for those procedures). Note that an assignment to default-random-source does not change random-integer or random-real; it is also strongly recommended not to assign a new value.