Function add

pub fn add<U, F>(
    builder: &mut ConstraintSystemBuilder<'_, U, F>,
    name: impl ToString,
    xin: OracleId,
    yin: OracleId,
    flags: Flags,
) -> Result<OracleId, Error>
where
    U: PackScalar<F> + PackScalar<BinaryField1b> + Pod,
    F: TowerField,