code: def unify_walk(vil, l, U):
      """
      Unifies VIL's inner Variable to OrV(list).
  
      """
      v = vil.variable
      ov = OrVariable("?", l)
      return unify_walk(v, ov, U)
  
imports: from __future__ import absolute_import, print_function, division
  from copy import copy
  from functools import partial
  from theano.gof.utils import ANY_TYPE, comm_guard, FALL_THROUGH, iteritems
label_desc: Use image node_id 12 for calling a global function with example usage: unify_walk(vil, l, U) and returns: unify_walk