code: def tril_indices_from(arr, k=0):
      """
      Return the indices for the lower-triangle of arr.
  
      See `tril_indices` for full details.
  
      Parameters
      ----------
      arr : array_like
          The indices will be valid for square arrays whose dimensions are
          the same as arr.
      k : int, optional
          Diagonal offset (see `tril` for details).
  
      See Also
      --------
      tril_indices, tril
  
      Notes
      -----
      .. versionadded:: 1.4.0
  
      """
      if arr.ndim != 2:
          raise ValueError("input array must be 2-d")
      return tril_indices(arr.shape[-2], k=k, m=arr.shape[-1])
  
imports: from __future__ import division, absolute_import, print_function
  import functools
  from numpy.core.numeric import absolute, asanyarray, arange, zeros, greater_equal, multiply, ones, asarray, where, int8, int16, int32, int64, empty, promote_types, diagonal, nonzero
  from numpy.core.overrides import set_module
  from numpy.core import overrides
  from numpy.core import iinfo, transpose
label_desc: Use image node_id 20 for calling a global function with example usage: tril_indices_from(arr, k) and returns: tril_indices