def lift_x
import bend-collections@1.0.0.0/spec/crypto/secp256k1/schnorr.bend as Schnorrimport Base
import bend-collections@1.0.0.0/spec/crypto/secp256k1/curve.bend as CV
64def lift_x(+one: Nat, +x: Nat) -> Maybe<&2, CV.SPoint>:
65 lift_if(one, x, Nat.is_lt(x, p(one)))