pub fn add(a: BigInt, b: BigInt) -> BigInt

pub fn divide(a: BigInt, b: BigInt) -> BigInt

pub fn from_int(a: Int) -> BigInt

pub fn from_string(a: String) -> BigInt

pub fn modulo(a: BigInt, b: BigInt) -> BigInt

pub fn multiply(a: BigInt, b: BigInt) -> BigInt

pub fn power(a: BigInt, b: BigInt) -> BigInt

pub fn subtract(a: BigInt, b: BigInt) -> BigInt