Check whether a number is prime.

(a * b) % n Precondition: (a < n). Precondition: (b < n).

Perform a Miller-Rabin primality test on `n` using base `a`. Preconditions: `n` is odd, and at least as big as `a + 2`. Also, `2` is the smallest al

Find the smallest factor which divides n. Undefined unless (n > 1).

The string-length of this string (i.e., NOT including the null terminator).

(a + b) % n Precondition: (a < n). Precondition: (b < n).

(a / 2) % n Precondition: (a < n). Precondition: (n is odd). If `a` is even, this is of course simply `a / 2` (because `(a < n)` as a precondition).

Perform the Baillie-PSW test for primality. Returns `BAD_INPUT` for any number less than 2, `COMPOSITE` for any larger number that is _known_ to be p

Map `true` onto `1`, and `false` onto `0`. The conversions `true` -> `1` and `false` -> `0` are guaranteed by the standard. This is a branchless imp

(a - b) % n Precondition: (a < n). Precondition: (b < n).

Express any positive `n` as `(2^s * d)`, where `d` is odd. Preconditions: `n` is positive.

Find the largest power of `factor` which divides `n`. Undefined unless n > 0, and factor > 1.