Left-skewed Gumbel distribution

The probability density function for the left-skewed Gumbel distribution is:

.. math::

f(x) = \exp(x - e^x)

The cumulative distribution function is:

.. math::

F(x) = 1 - \exp(-e^x)

The following plots show the pdf and cdf:

.. image:: ../../../../tests/imgs/stats/continuous/gumbel_l/gumbel_lpdf.png :align: center :width: 480

.. image:: ../../../../tests/imgs/stats/continuous/gumbel_l/gumbel_lcdf.png :align: center :width: 480