code: def forward_cpu(self, x):
      if not available_cpu:
          raise ImportError(
              "SciPy is not available. Forward computation"
              " of erfinv in CPU cannot be done. " + str(_import_error)
          )
      self.retain_outputs((0,))
      return (
          utils.force_array(special.erfinv(x[0]), dtype=x[0].dtype),
      )
  
file_path: chainer/chainer/functions/math/erfinv.py
imports: import math
  import chainer
  from chainer.backends import cuda
  from chainer import function_node
  from chainer import utils
  from chainer.utils import type_check
label_desc: Use image node_id 3 for calling the ErfInv obj's underlying member method code with example usage: obj.forward_cpu(x) and returns: utils