NewModulusFromBig creates a new Modulus from a [big.Int].

NewNat returns a new nat with a size of zero, just like new(Nat), but with the preallocated capacity to hold a number of up to preallocTarget bits.

Modulus is used for modular arithmetic, precomputing relevant constants.

Nat represents an arbitrary natural number Each Nat has an announced length, which is the number of limbs it has stored.