code: def f4(x):
      r"""Piecewise linear, left- and right- discontinuous at x=1, the root."""
      if x > 1:
          return 1.0 + 0.1 * x
      if x < 1:
          return -1.0 + 0.1 * x
      return 0
  
imports: from random import random
  import numpy
  from scipy.optimize import zeros
label_desc: Use image node_id 10 for calling a global function with example usage: f4(x) and returns: int, unknown, unknown