code: def main():
      x = Symbol("x")
      y = Symbol("y")
  
      mplot3d(
          x**2 - y**2, (x, -10.0, 10.0, 20), (y, -10.0, 10.0, 20)
      )
  
imports: import sys
  from sample import sample
  from sympy import Symbol
  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