code: def A1():
      diffeq = lambda t, y: -y
      init = lambda: (torch.tensor(0.0), torch.tensor(1.0))
      solution = lambda t: torch.exp(-t)
      return diffeq, init, solution
  
imports: import math
  import torch
label_desc: Use image node_id 1 for calling a global function with example usage: A1() and returns: diffeq,  init,  solution