.. necessary_conditional_entropy.rst
.. py:module:: dit.multivariate.necessary_conditional_entropy

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Necessary Conditional Entropy
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The necessary conditional entropy :cite:`cuff2010coordination` quantifies the amount of information that a random variable :math:`X` necessarily must carry above and beyond the mutual information :math:`\I{X : Y}` to actually contain that mutual information:

.. math::

   \H{X \dagger Y} = \H{ X \mss Y | Y}

API
===

.. autofunction:: necessary_conditional_entropy