code: def main():
      x = Symbol("x")
  
      # mplot2d(log(x), (x, 0, 2, 100))
      # mplot2d([sin(x), -sin(x)], (x, float(-2*pi), float(2*pi), 50))
      mplot2d(
          [sqrt(x), -sqrt(x), sqrt(-x), -sqrt(-x)], (x, -40.0, 40.0, 80)
      )
  
imports: import sys
  from sample import sample
  from sympy import sqrt, Symbol
  from sympy.utilities.iterables import is_sequence
  from sympy.external import import_module
label_desc: Use image node_id 2 for calling a global function with example usage: main() without return types