ufv_unstack_axes
================

.. py:function:: t3toolbox.backend.ufv_operations.ufv_unstack_axes(data, n_supercores, axes)

   .. code-block:: python

      def ufv_unstack_axes(
              data:         typ.Tuple,        # (*supercores, shape, masks): n_supercores arrays, int-tuple, 4-tuple of masks
              n_supercores: int,              # 4 (frame) or 2 (variations)
              axes:         typ.Sequence[int],  # the array axes to peel into tree levels (a CONTIGUOUS run within the stack)
      ):  # -> nested tuple (shaped like the peeled axes) of bv .data leaves carrying the remaining stack


   Unstack a bv ``.data`` tuple along the GIVEN array axes (a sub-run of the stack), leaving the rest.

   Generalizes :py:func:`ufv_unstack` (which peels the whole stack) to a contiguous sub-run -- the
   primitive the tangent layer needs to split a ``K + C`` variation stack into just its ``K`` part or just
   its ``C`` part. The supercores and all four rank masks slice along ``axes`` (they share those stack-axis
   positions; the masks' leading ``d`` vs ``d+1`` is irrelevant since only ``axes`` are touched); ``shape``
   is shared and replicated onto every leaf.