- prime? zprocedure
- z
- integer
Returns #t if z is a prime, #f otherwise.
Formally, an integer z is prime when the only positive divisors of z are 1 and (abs z).
The positive primes below 20 are:
> (filter prime? (iota 20 1)) (2 3 5 7 11 13 17 19)
The corresponding negative primes are:
> (filter prime? (iota 20 0 -1)) (-2 -3 -5 -7 -11 -13 -17 -19)
Wikipedia: Prime Number