.. _combinations-doc: .. ipython:: python :suppress: from rateslib.instruments import * from datetime import datetime as dt ************************************** Utilities and Instrument Combinations ************************************** Combinations allow common interbank traded structures to be created, and :class:`~rateslib.instruments.Value` is a null object typically used to directly parametrize a :ref:`Curve` via a :class:`~rateslib.solver.Solver` .. inheritance-diagram:: rateslib.instruments.Fly rateslib.instruments.Spread rateslib.instruments.Value rateslib.instruments.Portfolio :private-bases: :parts: 1 .. autosummary:: rateslib.instruments.Value rateslib.instruments.Spread rateslib.instruments.Fly rateslib.instruments.Portfolio