code: def combine_event_functions(event_fn, t0, y0):
      """
      We ensure all event functions are initially positive,
      so then we can combine them by taking a min.
      """
      with torch.no_grad():
          initial_signs = torch.sign(event_fn(t0, y0))
  
      def combined_event_fn(t, y):
          c = event_fn(t, y)
          return torch.min(c * initial_signs)
  
      return combined_event_fn
  
imports: import math
  import torch
label_desc: Use image node_id 2 for calling a global function with example usage: combine_event_functions(event_fn, t0, y0) and returns: combined_event_fn, torch